Re-enable suppression of logging event dictionary parsing errors

[gshank]

resolves #202

Description

Instead of using sys.modules to detect the presence of pytest, use the "PYTEST_CURRENT_TEST" environment variable. Also include the original exception in the logged error for easier debugging.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR
• I have run changie new to create a changelog entry

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.33%. Comparing base (8f2b1d5) to head (fcaf56f).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #203      +/-   ##
==========================================
+ Coverage   68.28%   68.33%   +0.04%     
==========================================
  Files          52       52              
  Lines        3374     3373       -1     
==========================================
+ Hits         2304     2305       +1     
+ Misses       1070     1068       -2     

Flag	Coverage Δ
unit	68.33% <100.00%> (+0.04%)	⬆️

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

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