BUILD-9058 reuse BUILD_NUMBER from env

[julien-carsique-sonarsource]

BUILD-9058

The GitHub cache used by get-build-number is not reliable and can be desynchronized between two jobs.
To circumvent, this PR makes it possible to pass the BUILD_NUMBER through environment, in which case, the get-build-number action will skip its steps.

Add tests to check for the behavior.

Tested with

• https://github.com/SonarSource/sonar-dummy/pull/483
• BUILD-9058 reuse BUILD_NUMBER from env sonar-dummy-gradle-oss#284

[sonarqubecloud]

🤖 Pull Request summary

Enhances build number action to support environment variable reuse.

• Added env variable support: Action now reuses BUILD_NUMBER from environment if present, skipping cache/increment logic
• Enhanced testing: Added comprehensive test coverage including stability across calls and environment variable reuse scenarios
• Simplified promote action: Removed conditional logic for build number retrieval
• Improved job organization: Added summary job using alls-green action to aggregate test results

Review focus: The new environment variable precedence logic and conditional step execution in the composite action - ensure the skip logic properly prevents unnecessary API calls and caching operations.

💬 Please send your feedback

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud