chore: Release v0.39.0

[MeltyBot]

Prepare MeltanoSDK v0.39.0 for release.

Checklist:

• Check that the right version is set in all the files.
• Groom the changelog for wording or missing entries.
• Merge this PR once everything looks good.

Release Draft

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📚 Documentation preview 📚: https://meltano-sdk--2568.org.readthedocs.build/en/2568/

[codspeed-hq]

CodSpeed Performance Report

Merging #2568 will not alter performance

_{Comparing release/v0.39.0 (fa56547) with main (1dce229)}

Summary

✅ 6 untouched benchmarks

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.47%. Comparing base (1dce229) to head (fa56547).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2568   +/-   ##
=======================================
  Coverage   89.47%   89.47%           
=======================================
  Files          58       58           
  Lines        4799     4799           
  Branches      937      937           
=======================================
  Hits         4294     4294           
  Misses        352      352           
  Partials      153      153           

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