CompatHelper: bump compat for JLD2 to 0.6, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the JLD2 package from 0.4, 0.5 to 0.4, 0.5, 0.6.
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 88.2%. Comparing base (6492efc) to head (f31ee38).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@          Coverage Diff           @@
##           master     #89   +/-   ##
======================================
  Coverage    88.2%   88.2%           
======================================
  Files          19      19           
  Lines        1013    1013           
======================================
  Hits          893     893           
  Misses        120     120           

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.