CompatHelper: bump compat for JLArrays to 0.3 for package test, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the JLArrays package from 0.2.0 to 0.2.0, 0.3 for package test.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.19%. Comparing base (6ddbe9d) to head (32698d6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #27   +/-   ##
=======================================
  Coverage   75.19%   75.19%           
=======================================
  Files           7        7           
  Lines         129      129           
=======================================
  Hits           97       97           
  Misses         32       32           

Flag	Coverage Δ
docs	0.00% <ø> (ø)

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