chore: Remove unused jRuby environment

[arkirchner]

The jRuby environment has no supported/maintained docker image.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.57%. Comparing base (9374bce) to head (6caa9de).
Report is 43 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3010      +/-   ##
==========================================
+ Coverage   69.60%   70.57%   +0.96%     
==========================================
  Files         214      215       +1     
  Lines        6821     6980     +159     
==========================================
+ Hits         4748     4926     +178     
+ Misses       2073     2054      -19     

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