Tweak Sentry SDK setup

[chromy]

Make two changes to what we report to Sentry for crashes:

1. Set 'environment' to SENTRY_REGION / SENTRY_ENVIRONMENT so rather
   than being 'production' or 'development' it's 'us', 'de', etc.
2. Set 'release' to the git sha we are building at.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.75%. Comparing base (e3c1bcd) to head (810b06f).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #291      +/-   ##
==========================================
+ Coverage   77.73%   77.75%   +0.01%     
==========================================
  Files         141      141              
  Lines       11086    11084       -2     
  Branches     1184     1183       -1     
==========================================
  Hits         8618     8618              
+ Misses       2048     2046       -2     
  Partials      420      420              

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