Multiple path separators causes bad requests 

<!-- Summary. -->
I'm assuming that change in https://github.com/psf/requests/pull/6644 is the cause of this changed behavior that operations with // in path fails. It seems to be related to Authentication as it is the only thing I could find that does not get trimmed by the change in 6644.

## Expected Result

Similar behavior as before 2.32.0

## Actual Result

Request captured by wireshark, note that this is the second request as the first got a 401

Hypertext Transfer Protocol
    POST /axis-cgi/capturemode.cgi HTTP/1.1\r\n
    Host: 192.168.0.1\r\n
    User-Agent: python-requests/2.32.3\r\n
    Accept-Encoding: gzip, deflate, zstd\r\n
    Accept: */*\r\n
    Connection: keep-alive\r\n
    Content-Length: 50\r\n
     [truncated]Authorization: Digest username="root", realm="AXIS_B8A44F45D62F", nonce="UKH3vekeBgA=2b0d57c2d8b8eb15307576e30309cb7b23a2304c", uri="//axis-cgi/capturemode.cgi", response="0a51943f746a0d88c6574f662b457a9c", algorithm="MD5", qo
         username="root"
         realm="AXIS_B8A44F45D62F"
         nonce="UKH3vekeBgA=2b0d57c2d8b8eb15307576e30309cb7b23a2304c"
         uri="//axis-cgi/capturemode.cgi"
         response="0a51943f746a0d88c6574f662b457a9c"
         algorithm="MD5"
         qop="auth"
         nc=00000001
    \r\n
    [Full request URI: http://172.26.21.128/axis-cgi/capturemode.cgi]
    [HTTP request 2/2]
    [Prev request in frame: 10]
    [Response in frame: 19]
    File Data: 50 bytes
    Data (50 bytes)

Response:
Hypertext Transfer Protocol
    HTTP/1.1 400 Bad Request\r\n
    Date: Mon, 05 Aug 2024 06:25:23 GMT\r\n
    Server: Apache/2.4.58 (Unix) OpenSSL/3.0.13\r\n
    X-Content-Type-Options: nosniff\r\n
    X-Frame-Options: SAMEORIGIN\r\n
    X-XSS-Protection: 1; mode=block\r\n
     [truncated]Content-Security-Policy: default-src 'self'; frame-ancestors 'self'; connect-src 'self' https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://*.axis.com mediastream: blob:; script
    Content-Length: 226\r\n
    Connection: close\r\n
    Content-Type: text/html; charset=iso-8859-1\r\n
    \r\n
    [HTTP response 2/2]
    [Time since request: 0.001411000 seconds]
    [Prev request in frame: 10]
    [Prev response in frame: 13]
    [Request in frame: 16]
    [Request URI: http://192.168.0.1/axis-cgi/capturemode.cgi]
    File Data: 226 bytes

## Reproduction Steps
This was run at a axis camera

```python
import requests

url = "http://192.168.01//axis-cgi/capturemode.cgi"
body = {
            "apiVersion": "1.0",
            "method": "getCaptureModes"}

auth = requests.auth.HTTPDigestAuth("root", "pass")
response = requests.post(url=url, data=json.dumps(body),
                                              auth=auth, proxies=dict(http=None, https=None))
```

## System Information

    $ python -m requests.help

```json
{
  "chardet": {
    "version": null
  },
  "charset_normalizer": {
    "version": "3.3.2"
  },
  "cryptography": {
    "version": "42.0.8"
  },
  "idna": {
    "version": "3.7"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.11.2"
  },
  "platform": {
    "release": "6.1.0-21-amd64",
    "system": "Linux"
  },
  "pyOpenSSL": {
    "openssl_version": "30200020",
    "version": "24.1.0"
  },
  "requests": {
    "version": "2.32.3"
  },
  "system_ssl": {
    "version": "300000b0"
  },
  "urllib3": {
    "version": "2.2.2"
  },
  "using_charset_normalizer": true,
  "using_pyopenssl": true
}
```