Refactor data task

[torresga]

Summary

• Replaces the two-task setup (find_or_create_rails_releases + update_rails_releases) with a single canonical data:sync_rails_releases task that creates and updates Rails releases in one pass
• Adds guards in the task to raise early if minimum_ruby_version or minimum_bundler_version are missing for any version entry
• Adds model-level presence validations for minimum_ruby_version and minimum_bundler_version on RailsRelease
• Updates README setup instructions to reference the new task name

Test plan

• Run rake data:sync_rails_releases on a fresh database and verify all releases are created with required fields populated
• Verify that removing minimum_ruby_version from an entry in the task raises an error before any DB writes
• Verify that saving a RailsRelease without minimum_ruby_version or minimum_bundler_version fails validation

Fixes #145

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.38%. Comparing base (1676056) to head (c1d463b).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #155       +/-   ##
===========================================
- Coverage   87.00%   63.38%   -23.63%     
===========================================
  Files          48       48               
  Lines         708      710        +2     
===========================================
- Hits          616      450      -166     
- Misses         92      260      +168     

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[torresga]

Are these the validations you had in mind, @JuanVqz? Between the spec failures that arise due to this change and this call to RailsRelease.create in https://github.com/railsbump/app/blob/main/app/services/rails_releases/create.rb#L13 maybe we shouldn't be validating whether these values are present after all? Please let me know what you think.

[JuanVqz]

To me that service is dead code. we probably can remove it since we have the lib/tasks/data.rake.