feat(release-tracks): support virtual schedule updates

[seansica]

Persist validated schedule replacements without cloning snapshots and expose active schedules to configuration clients.

Relates to mitre-attack/attack-workbench-frontend#956

[codecov-commenter]

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Codecov Report

❌ Patch coverage is 97.08738% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.43%. Comparing base (eb3711a) to head (ac3dd03).

Files with missing lines	Patch %	Lines
...elease-tracks/release-track-registry.repository.js	84.21%	3 Missing ⚠️
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Additional details and impacted files

@@            Coverage Diff             @@
##             beta     #494      +/-   ##
==========================================
+ Coverage   80.38%   80.43%   +0.04%     
==========================================
  Files         243      243              
  Lines       38538    38636      +98     
  Branches     4661     4681      +20     
==========================================
+ Hits        30980    31075      +95     
- Misses       7471     7474       +3     
  Partials       87       87              

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[github-actions]

🎉 This PR is included in version 4.20.0-beta.27 🎉

The release is available on:

• v4.20.0-beta.27
• GitHub release

Your semantic-release bot 📦🚀

[github-actions]

🎉 This PR is included in version 4.21.0 🎉

The release is available on:

• v4.21.0
• GitHub release

Your semantic-release bot 📦🚀