chore: Fix deprecated unittest aliases for Python 3.11 compatibility.

[tirkarthi]

SUMMARY

Fix deprecated unittest aliases for Python 3.11 compatibility. The deprecated aliases have been removed in python/cpython#28268 in Python 3.11. Similar to #10195

TESTING INSTRUCTIONS

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[villebro]

Nice, thanks for the first Python 3.11 support PR! 🎉

[codecov]

Codecov Report

Merging #17562 (607b845) into master (870d2ab) will increase coverage by 0.21%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #17562      +/-   ##
==========================================
+ Coverage   76.81%   77.02%   +0.21%     
==========================================
  Files        1049     1049              
  Lines       56671    56682      +11     
  Branches     7851     7851              
==========================================
+ Hits        43529    43660     +131     
+ Misses      12889    12769     -120     
  Partials      253      253              

Flag	Coverage Δ
hive	81.61% <ø> (?)
mysql	82.03% <ø> (+<0.01%)	⬆️
postgres	82.04% <ø> (+<0.01%)	⬆️
presto	81.91% <ø> (?)
python	82.53% <ø> (+0.41%)	⬆️
sqlite	81.72% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
superset/utils/core.py	89.76% <0.00%> (+0.11%)	⬆️
superset/db_engine_specs/base.py	88.54% <0.00%> (+0.38%)	⬆️
superset/models/core.py	90.00% <0.00%> (+0.73%)	⬆️
superset/connectors/sqla/models.py	88.42% <0.00%> (+1.57%)	⬆️
superset/views/database/mixins.py	82.75% <0.00%> (+1.72%)	⬆️
superset/db_engine_specs/trino.py	63.85% <0.00%> (+4.13%)	⬆️
superset/db_engine_specs/presto.py	90.39% <0.00%> (+6.88%)	⬆️
superset/db_engine_specs/hive.py	87.25% <0.00%> (+16.98%)	⬆️
superset/db_engines/hive.py	85.18% <0.00%> (+85.18%)	⬆️

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[tirkarthi]

It seems the pip packages are not cached which causes the install step to download always from PyPI. I have added caching as per docs in https://github.com/actions/setup-python#caching-packages-dependencies