chore(helm): drop CI workflow + ci/ fixtures + CONTRIBUTING.md

The helm-unittest suites in helm/sim/tests/ and the helm test hook
in helm/sim/templates/tests/ stay — those are chart-internal quality
scaffolding, not CI. Removed:

- .github/workflows/helm-chart.yml
- helm/sim/ci/*.yaml (5 render fixtures used only by the workflow)
- helm/sim/CONTRIBUTING.md (mostly documented those gates)
- dead /ci/ and /CONTRIBUTING.md entries in .helmignore

Author: waleedlatif1

.github/workflows/helm-chart.yml

@@ -23,8 +23,6 @@
 .vscode/
 # Repo tooling — not part of the chart artifact (anchored to chart root)
 /.claude/
-/CONTRIBUTING.md
-/ci/
 # Examples — published in-repo, not in the packaged chart
 /examples/
 # Unit-test suites (helm-unittest) — distinct from templates/tests/ which IS shipped