DM-55179: Add v30.0.8 release notes

[timj]

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 74.20%. Comparing base (dac4343) to head (6d8bbae).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #52   +/-   ##
=======================================
  Coverage   74.20%   74.20%           
=======================================
  Files         114      114           
  Lines       13183    13183           
=======================================
  Hits         9783     9783           
  Misses       3400     3400           

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