Repository: sopel-irc/sopel

Issue:
UTF-8 Check fails on windows in Powershell
### Description
The current version of sopel in pip (py3.9.6) and from git master both prompt this message upon running sopel even with a utf8 configuration:

> WARNING!!! You are running with a non-UTF8 locale environment variable (e.g. LC_ALL is set to "C"), which makes Python 3 do stupid things. If you get strange errors, please set it to something like "en_US.UTF-8".

Despite having a "English_United States", "utf8" locale from python.

### Reproduction steps
Pull into a fresh python dev environment on windows 10.
Install sopel via pip or from source.
Run sopel.

### Expected behavior
To not get a warning about UTF-8 since it's configured.

### Logs
```
(.venv) PS C:\Users\Michael\Documents\Visual Studio Projects\Python\sopel> $PSVersionTable     

Name                           Value
----                           -----
PSVersion                      7.1.4
PSEdition                      Core
GitCommitId                    7.1.4
OS                             Microsoft Windows 10.0.19041
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

(.venv) PS C:\Users\Michael\Documents\Visual Studio Projects\Python\sopel> Get-WinSystemLocale 

LCID             Name             DisplayName
----             ----             -----------
1033             en-US            English (United States)

(.venv) PS C:\Users\Michael\Documents\Visual Studio Projects\Python\sopel> echo $OutputEncoding

Preamble          :      
BodyName          : utf-8
EncodingName      : Unicode (UTF-8)
HeaderName        : utf-8
WebName           : utf-8
WindowsCodePage   : 1200
IsBrowserDisplay  : True
IsBrowserSave     : True
IsMailNewsDisplay : True
IsMailNewsSave    : True
IsSingleByte      : False
EncoderFallback   : System.Text.EncoderReplacementFallback
DecoderFallback   : System.Text.DecoderReplacementFallback
IsReadOnly        : True
CodePage          : 65001


(.venv) PS C:\Users\Michael\Documents\Visual Studio Projects\Python\sopel> py
Python 3.9.6 (tags/v3.9.6:db3ff76, Jun 28 2021, 15:26:21) [MSC v.1929 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
>>> locale.getlocale()
('English_United States', 'utf8')
>>> exit()
```

### Environment
- Sopel `.version`: 8.0.0
- Sopel installed via: pip && source
- Python version: 3.9.6
- Operating system: Windows 10
- IRCd `/version`: N/A
- Relevant plugins: N/A



Discussion:

Resolving patch:
diff --git a/sopel/__init__.py b/sopel/__init__.py
--- a/sopel/__init__.py
+++ b/sopel/__init__.py
@@ -34,7 +34,7 @@
 ]
 
 loc = locale.getlocale()
-if not loc[1] or 'UTF-8' not in loc[1]:
+if not loc[1] or ('UTF-8' not in loc[1] and 'utf8' not in loc[1]):
     print('WARNING!!! You are running with a non-UTF8 locale environment '
           'variable (e.g. LC_ALL is set to "C"), which makes Python 3 do '
           'stupid things. If you get strange errors, please set it to '


Test patch: