docs: CLAUDE.md shallow-clone-race workaround note is stale (fixed upstream)

CLAUDE.md documents that the \`Build k8s-manifests\` workflow "intermittently fails with \`fatal: shallow file has changed since we read it\` — rerun the workflow." That race was fixed upstream in hologit (JarvusInnovations/hologit#450, closed); the rerun guidance is no longer needed once this repo's projection runs a hologit release containing the fix.

Verify the projector action is on a fixed release, then drop the workaround note so agents/operators stop treating reruns as standard procedure.

Start with CLAUDE.md and the Build k8s-manifests workflow. Verify that its projector action uses a hologit release containing the fix from hologit#450, then remove the stale shallow-clone-race workaround note. Done means the fixed release is confirmed and the rerun guidance is gone.

Written by the indexing model from the issue text.