[SDTEST-1266] Add Github Actions tests

[TonyCTHsu]

What does this PR do?

Github Actions Migration for Unit testing.

Includes additionally:

• migrates linting task from circleci to GHA
• removes codecov completely (it creates noise and total code coverage metric isn't useful)
• removes edge builds from circleci (they provide zero value)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.50%. Comparing base (e15f77a) to head (fe47f1e).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #258      +/-   ##
==========================================
- Coverage   98.50%   98.50%   -0.01%     
==========================================
  Files         298      298              
  Lines       14093    14092       -1     
  Branches      682      681       -1     
==========================================
- Hits        13883    13882       -1     
  Misses        210      210              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.