[OPIK-7258] [GHA] fix: regenerate Helm chart README in release version-bump commit

[JetoPistola]

Details

The release workflow (release.yaml, job commit-all-version-changes) already rewrites Chart.yaml version/appVersion and pushes to main, but never regenerated the helm-docs-derived README.md badges — so the chart README lagged one release behind. The staleness only surfaced when the next PR touching deployment/helm_chart/opik/** tripped the helm-docs pre-commit hook / update_helm_readme.yaml gate, forcing that author to bump the badge in unrelated work.

• Added a "Regenerate Helm chart README" step right after the Chart.yaml bump, using the same losisin/helm-docs-github-action@v1 (git-push: false) that update_helm_readme.yaml and the local pre-commit hook use, so CI and local stay in agreement.
• Staged the regenerated README.md alongside the existing version files so it rides the same bot commit to main — no separate PR, no drift window.
• Also clears the current 2.1.17 → 2.1.18 badge drift already present on main.

Change checklist

• User facing
• Documentation update

Issues

• OPIK-7258

AI-WATERMARK

AI-WATERMARK: yes

• Tools: Claude Code
• Model(s): Opus 4.8
• Scope: full implementation
• Human verification: local helm-docs run reproducing the badge update + actionlint; code review

Testing

• Ran the exact pre-commit helm-docs image against the bumped chart to confirm the mechanism produces only the badge update and nothing else:
  docker run --rm -v "$PWD/deployment/helm_chart/opik:/helm-docs" jnorwood/helm-docs:v1.14.2 --chart-search-root=/helm-docs → README Version/AppVersion badges updated 2.1.17 → 2.1.18, diff limited to the two badge lines.
• pre-commit run actionlint --files .github/workflows/release.yaml → Passed.
• No Java/FE/SDK code changed, so backend/frontend/SDK quality suites are N/A.

Documentation

N/A — no user-facing documentation changes. The only doc touched is the auto-generated chart README.md badge, which this change now maintains automatically.

[github-actions]

⏱️ pre-commit per-hook timing

Hook	Description	Result	Duration
⚙️ actionlint — github workflows	Lint GitHub Actions workflows	✅	0.83s
Total (1 ran)			0.83s

⏭️ 39 skipped (no matching files changed)

Hook	Description	Result
🐍 trim trailing whitespace — python sdk	Strip trailing whitespace	⏭️
🐍 fix end of files — python sdk	Ensure files end in a newline	⏭️
🐍 ruff — python sdk	Lint + autofix Python (ruff)	⏭️
🐍 ruff-format — python sdk	Format Python code (ruff)	⏭️
🐍 mypy — python sdk	Static type check	⏭️
🤖 trim trailing whitespace — optimizer	Strip trailing whitespace	⏭️
🤖 fix end of files — optimizer	Ensure files end in a newline	⏭️
🤖 check yaml — optimizer	Validate YAML syntax	⏭️
🤖 check json — optimizer	Validate JSON syntax	⏭️
🤖 check toml — optimizer	Validate TOML syntax	⏭️
🤖 check for added large files — optimizer	Block large files (>1MB)	⏭️
🔐 detect private key — optimizer	Block committed private keys	⏭️
🤖 check for merge conflicts — optimizer	Block merge-conflict markers	⏭️
🤖 check for case conflicts — optimizer	Block case-only name clashes	⏭️
🤖 pyupgrade — optimizer	Modernize Python syntax	⏭️
🤖 ruff — optimizer	Lint + autofix Python (ruff)	⏭️
🤖 ruff-format — optimizer	Format Python code (ruff)	⏭️
🤖 mypy — optimizer	Static type check	⏭️
📓 nbstripout — optimizer notebooks	Strip notebook output	⏭️
📝 markdownlint — optimizer	Lint Markdown	⏭️
🔤 codespell — optimizer	Fix common misspellings	⏭️
📊 radon cc — optimizer	Cyclomatic-complexity gate	⏭️
📊 radon raw — optimizer	Raw size metrics gate	⏭️
📊 xenon — optimizer	Fail on complexity thresholds	⏭️
📊 lizard — optimizer	Cyclomatic-complexity gate	⏭️
🧹 vulture — optimizer	Find dead code	⏭️
🛡️ trim trailing whitespace — guardrails	Strip trailing whitespace	⏭️
🛡️ fix end of files — guardrails	Ensure files end in a newline	⏭️
🛡️ ruff — guardrails	Lint + autofix Python (ruff)	⏭️
🛡️ ruff-format — guardrails	Format Python code (ruff)	⏭️
🛡️ mypy — guardrails	Static type check	⏭️
⚓ helm-docs	Regenerate Helm chart README	⏭️
block non-public FE plugins	Block non-public FE plugins	⏭️
☕ spotless — java backend	Format Java code	⏭️
🧪 pre-commit wrapper smoke tests	Self-test the wrapper scripts	⏭️
🌐 eslint — frontend	Lint + autofix JS/TS	⏭️
🌐 typecheck — frontend	Whole-project tsc type check	⏭️
📘 eslint — typescript sdk	Lint + autofix JS/TS	⏭️
📘 typecheck — typescript sdk	Whole-project tsc type check	⏭️