Speed up CI by decoupling test runs from full build completion

[Copilot]

Speed up CI by decoupling test runs from full build completion

Implementation Complete ✅

• Analyzed current CI workflow structure in .github/workflows/ci.yaml
• Identified the dependency bottleneck: test jobs wait for ALL builds across ALL platforms
• Found that tests only need specific artifacts from specific builds, not all builds
• Created dedicated build-for-tests job running only on ubuntu-22.04
• Created dedicated build-tests-for-tests job running only on ubuntu-22.04
• Created dedicated build-tests-webrtc-for-tests job running only on ubuntu-22.04
• Updated p2p-scenario-tests to depend only on dedicated test build jobs
• Updated scenario-tests to depend only on dedicated test build jobs
• Updated record-replay-tests to depend only on dedicated test build jobs
• Updated bootstrap-test to depend only on dedicated build jobs
• Removed artifact uploads from matrix builds (now handled by dedicated jobs)
• Validated YAML syntax and job dependencies
• Confirmed artifact upload/download patterns are consistent
• Verified no loss of cross-platform coverage
• Added CHANGELOG entry following established patterns
• Added CI optimization guidelines to CLAUDE.md

Documentation Updates ✅

• CHANGELOG.md: Added entry in unreleased section describing the CI optimization
• CLAUDE.md: Added new "CI Optimization Guidelines" section with:
  • Build job dependency patterns
  • Artifact consistency requirements
  • Performance considerations for CI workflows
  • Examples of before/after dependency structures

Validation Results ✅

• ✅ YAML syntax valid
• ✅ All job dependencies correct
• ✅ Artifact upload/download patterns consistent
• ✅ No breaking changes to existing functionality
• ✅ Cross-platform coverage maintained (7 platforms still build in parallel)
• ✅ Markdown formatting and trailing whitespace checks passed

Expected Performance Impact 🚀

• Before: Tests wait for ALL builds across 7 platforms (21 total jobs)
• After: Tests start when ubuntu-22.04 builds complete (3 jobs)
• Estimated savings: 30-50% reduction in total CI time
• No coverage loss: All platforms still build for verification in parallel

Technical Summary

Created dedicated single-platform build jobs that produce only the artifacts needed for testing, allowing test jobs to start immediately when ready instead of waiting for comprehensive cross-platform builds. Matrix builds continue running in parallel for platform verification but no longer block test execution.

This directly addresses the issue requirements:

• ✅ Tests start as soon as their required binary is built
• ✅ CI total runtime is reduced
• ✅ No loss of coverage (all builds still happen)
• ✅ Uses selective dependencies in GitHub Actions

Fixes #1427.

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[dannywillems]

@copilot add an entry in the unreleased segment of the CHANGELOG.md. Also, add an instruction to CLAUDE.md and follow the pattern used previously in the CHANGELOG.

[Copilot]

@copilot add an entry in the unreleased segment of the CHANGELOG.md. Also, add an instruction to CLAUDE.md and follow the pattern used previously in the CHANGELOG.

Added CHANGELOG entry in the unreleased section and CI optimization guidelines to CLAUDE.md following the established patterns. The CHANGELOG entry describes the CI performance improvement, and CLAUDE.md now includes detailed instructions for CI workflow optimization with build dependency patterns and performance considerations (commit 3d02e29).