Request to link-local IPv6 address of service not listening for IPv6 tries all network interfaces, fails five times for each

Summary.

## Expected Result

Something more like what cURL does, trying the primary/first interface in the list, failing, then reverting to IPv4.

## Actual Result

Requests tries each networking interface shown by the Windows ipconfig command (three in my case) on the link-local IPv6 address. Since the service in question isn't listening for IPv6, the TCP connection fails, and Requests tries again four more times before moving on to the next interface's link-local IPv6 address, which proceeds the same. Each interface takes about 2 seconds to get through this, taking six seconds in total before falling back to IPv4, which succeeds.

## Reproduction Steps

```python
import requests
r =requests.get('http://hostname-with-link-local-IPv6-address:8001/')

```

## System Information

    $ python -m requests.help

```
{
  "chardet": {
    "version": "4.0.0"
  },
  "cryptography": {
    "version": ""
  },
  "idna": {
    "version": "2.10"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.8.1"
  },
  "platform": {
    "release": "10",
    "system": "Windows"
  },
  "pyOpenSSL": {
    "openssl_version": "",
    "version": null
  },
  "requests": {
    "version": "2.25.1"
  },
  "system_ssl": {
    "version": "1010104f"
  },
  "urllib3": {
    "version": "1.26.6"
  },
  "using_pyopenssl": false
}
```

This is using Python 3.8.1 on Windows 10 x64 Version 21H1 (OS Build 19043.1052). Running ipconfig shows three interfaces: one Ethernet, and two VMware Network Adapters. The following Wireshark transcript (with anonymized link-local addresses and port number; 8001 is not the actual port I'm using) shows the three sets of failed IPv6 sessions and eventual fallback to IPv4.

```
1	0.000000	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	55447 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
2	0.000017	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 55447 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
3	0.504934	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	[TCP Retransmission] 55447 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
4	0.504960	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 55447 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
5	1.016384	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	[TCP Retransmission] 55447 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
6	1.016426	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 55447 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
7	1.525929	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	[TCP Retransmission] 55447 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
8	1.525955	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 55447 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
9	2.035264	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	[TCP Retransmission] 55447 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
10	2.035294	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 55447 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
11	2.035705	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	76	55454 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
12	2.035717	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	64	8001 → 55454 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
13	2.541853	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	76	[TCP Retransmission] 55454 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
14	2.541872	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	64	8001 → 55454 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
15	3.049899	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	76	[TCP Retransmission] 55454 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
16	3.049927	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	64	8001 → 55454 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
17	3.562027	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	76	[TCP Retransmission] 55454 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
18	3.562048	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	64	8001 → 55454 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
19	4.071151	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	76	[TCP Retransmission] 55454 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
20	4.071187	2001:db8::8a2e:370:7335	2001:db8::8a2e:370:7335	TCP	64	8001 → 55454 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
21	4.071510	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	76	55456 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
22	4.071522	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	64	8001 → 55456 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
23	4.584244	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	76	[TCP Retransmission] 55456 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
24	4.584271	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	64	8001 → 55456 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
25	5.094989	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	76	[TCP Retransmission] 55456 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
26	5.095010	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	64	8001 → 55456 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
27	5.604492	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	76	[TCP Retransmission] 55456 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
28	5.604510	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	64	8001 → 55456 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
29	6.113265	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	76	[TCP Retransmission] 55456 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
30	6.113289	2001:db8::8a2e:370:7336	2001:db8::8a2e:370:7336	TCP	64	8001 → 55456 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
31	6.113658	172.16.254.1	172.16.254.1	TCP	56	55457 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65495 WS=256 SACK_PERM=1
32	6.113710	172.16.254.1	172.16.254.1	TCP	56	8001 → 55457 [SYN, ACK] Seq=0 Ack=1 Win=65535 Len=0 MSS=65495 WS=256 SACK_PERM=1
33	6.113771	172.16.254.1	172.16.254.1	TCP	44	55457 → 8001 [ACK] Seq=1 Ack=1 Win=2619648 Len=0
34	6.113800	172.16.254.1	172.16.254.1	HTTP	207	GET / HTTP/1.1 
35	6.113825	172.16.254.1	172.16.254.1	TCP	44	8001 → 55457 [ACK] Seq=1 Ack=164 Win=2619648 Len=0
36	6.122350	172.16.254.1	172.16.254.1	TCP	203	8001 → 55457 [PSH, ACK] Seq=1 Ack=164 Win=2619648 Len=159 [TCP segment of a reassembled PDU]
37	6.122374	172.16.254.1	172.16.254.1	TCP	44	55457 → 8001 [ACK] Seq=164 Ack=160 Win=2619392 Len=0
38	6.122415	172.16.254.1	172.16.254.1	HTTP	67	HTTP/1.1 200 OK  (text/html)
39	6.122425	172.16.254.1	172.16.254.1	TCP	44	55457 → 8001 [ACK] Seq=164 Ack=183 Win=2619392 Len=0
40	6.123083	172.16.254.1	172.16.254.1	TCP	44	55457 → 8001 [FIN, ACK] Seq=164 Ack=183 Win=2619392 Len=0
41	6.123103	172.16.254.1	172.16.254.1	TCP	44	8001 → 55457 [ACK] Seq=183 Ack=165 Win=2619648 Len=0
42	6.128661	172.16.254.1	172.16.254.1	TCP	44	8001 → 55457 [FIN, ACK] Seq=183 Ack=165 Win=2619648 Len=0
43	6.128714	172.16.254.1	172.16.254.1	TCP	44	55457 → 8001 [ACK] Seq=165 Ack=184 Win=2619392 Len=0
```

In contrast, cURL tries only the Ethernet interface, fails once, and rapidly falls back to IPv4.

```
1	0.000000	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	76	56252 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65475 WS=256 SACK_PERM=1
2	0.000015	2001:db8::8a2e:370:7334	2001:db8::8a2e:370:7334	TCP	64	8001 → 56252 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
3	0.211071	10.1.211.231	10.1.211.231	TCP	56	56253 → 8001 [SYN] Seq=0 Win=65535 Len=0 MSS=65495 WS=256 SACK_PERM=1
4	0.211142	10.1.211.231	10.1.211.231	TCP	56	8001 → 56253 [SYN, ACK] Seq=0 Ack=1 Win=65535 Len=0 MSS=65495 WS=256 SACK_PERM=1
5	0.211183	10.1.211.231	10.1.211.231	TCP	44	56253 → 8001 [ACK] Seq=1 Ack=1 Win=2619648 Len=0
6	0.211364	10.1.211.231	10.1.211.231	HTTP	140	GET / HTTP/1.1 
7	0.211387	10.1.211.231	10.1.211.231	TCP	44	8001 → 56253 [ACK] Seq=1 Ack=97 Win=2619648 Len=0
8	0.218706	172.16.254.1	10.1.211.231	TCP	203	8001 → 56253 [PSH, ACK] Seq=1 Ack=97 Win=2619648 Len=159 [TCP segment of a reassembled PDU]
9	0.218733	10.1.211.231	10.1.211.231	TCP	44	56253 → 8001 [ACK] Seq=97 Ack=160 Win=2619392 Len=0
10	0.218777	10.1.211.231	10.1.211.231	HTTP	67	HTTP/1.1 200 OK  (text/html)
11	0.218789	10.1.211.231	10.1.211.231	TCP	44	56253 → 8001 [ACK] Seq=97 Ack=183 Win=2619392 Len=0
12	0.219077	10.1.211.231	10.1.211.231	TCP	44	56253 → 8001 [FIN, ACK] Seq=97 Ack=183 Win=2619392 Len=0
13	0.219096	10.1.211.231	10.1.211.231	TCP	44	8001 → 56253 [ACK] Seq=183 Ack=98 Win=2619648 Len=0
14	0.226608	10.1.211.231	10.1.211.231	TCP	44	8001 → 56253 [FIN, ACK] Seq=183 Ack=98 Win=2619648 Len=0
15	0.226679	10.1.211.231	10.1.211.231	TCP	44	56253 → 8001 [ACK] Seq=98 Ack=184 Win=2619392 Len=0
```

This isn't a bug in requests, it also happens using other methods so it's a bug somewhere in Python itself, at least on Windows.