Minor package cleanup

[gwynne]

• Disable CodeQL CI, as GitHub hasn't fixed it yet
• Clean up badges in README
• Include latest revisions to images and theme settings in DocC catalog
• Make LOG_LEVEL env var work in tests
• Default the log level in tests to .info to match original (broken) logic

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.78%. Comparing base (dc9caf8) to head (d98d68a).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #464      +/-   ##
==========================================
- Coverage   61.82%   61.78%   -0.04%     
==========================================
  Files         125      125              
  Lines       10019    10019              
==========================================
- Hits         6194     6190       -4     
- Misses       3825     3829       +4     

see 2 files with indirect coverage changes