ci: lock ruby environment

[cvarjao]

Summary of Changes

Replace this text with a high-level summary of the changes included in this PR.

Related Issues

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Pull Request Checklist

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• All commits contain a DCO Signed-off-by line (we use the DCO GitHub app to enforce this);
• Updated LICENSE-3RD-PARTY.md for any added dependencies or vendored components;
• Updated documentation as needed for changed code and new or modified features;
• Added sufficient tests so that overall code coverage is not reduced.

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[codecov]

Codecov Report

Merging #991 (254ad41) into main (7c0eb18) will increase coverage by 0.05%.
The diff coverage is n/a.

❗ Current head 254ad41 differs from pull request most recent head d29b05c. Consider uploading reports for the commit d29b05c to get more accurate results

@@            Coverage Diff             @@
##             main     #991      +/-   ##
==========================================
+ Coverage   59.20%   59.26%   +0.05%     
==========================================
  Files         176      176              
  Lines        5091     5086       -5     
  Branches     1454     1452       -2     
==========================================
  Hits         3014     3014              
+ Misses       2051     2046       -5     
  Partials       26       26              

see 1 file with indirect coverage changes

[bryce-mcmath]

Looks good