DM-54588: Release notes for v30.0.6

[timj]

Do not include the news fragment from DM-54466 since that was describing a bug fix introduced in by the other ticket described in the release notes and so was never part of a public release.

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.50%. Comparing base (93b68a1) to head (fad684b).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #235   +/-   ##
=======================================
  Coverage   90.50%   90.50%           
=======================================
  Files          51       51           
  Lines        5626     5626           
  Branches      544      544           
=======================================
  Hits         5092     5092           
  Misses        436      436           
  Partials       98       98           

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