Update Python and Django versions and tests

[aleksihakli]

• Add Python 3.11 support
• Add Django 4.2 support
• Drop Python 3.7 support
• Drop Django 4.0 support
• Skip flaky checks on Django main and PyPy
• Deprecate common test mixins
• Use mock requests in Soundcloud tests
• Soundcloud sometimes answers 403 for requests
• Raise URL on soundcloud exceptions

[codecov[bot]]

Codecov Report

Merging #198 (b2510b1) into master (28a214b) will increase coverage by 0.49%. The diff coverage is 100.00%.

:exclamation: Current head b2510b1 differs from pull request most recent head ce72d33. Consider uploading reports for the commit ce72d33 to get more accurate results

@@            Coverage Diff             @@
##           master     #198      +/-   ##
==========================================
+ Coverage   98.45%   98.95%   +0.49%     
==========================================
  Files          17       16       -1     
  Lines         647      668      +21     
  Branches       39       66      +27     
==========================================
+ Hits          637      661      +24     
+ Misses          6        4       -2     
+ Partials        4        3       -1     

Impacted Files	Coverage Δ
embed_video/backends.py	97.46% <ø> (+1.89%)	:arrow_up:
embed_video/admin.py	100.00% <100.00%> (ø)
embed_video/tests/backends/tests_soundcloud.py	100.00% <100.00%> (ø)
embed_video/tests/backends/tests_vimeo.py	100.00% <100.00%> (ø)
embed_video/tests/backends/tests_youtube.py	100.00% <100.00%> (ø)
...video/tests/templatetags/tests_embed_video_tags.py	100.00% <100.00%> (ø)

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