fix(ci): remove weekly MSRV release run

docs/release-ci-matrix.md

@@ -4,8 +4,8 @@ MetaCrate has one routine code-ready signal: the `required` job in
 `.gitea/workflows/ci.yml`. It runs for every push and pull request on
 `ubuntu-latest`, has a hard 15-minute timeout, and cancels an older run for the
 same branch or pull request. `.gitea/workflows/release.yml` is the only other
-workflow. It is manual, weekly, and tag-only; it never runs for an ordinary
-source push or pull request.
+workflow. It runs only when manually dispatched or when a release tag is
+pushed; it never runs for an ordinary source push or pull request.
 
 The reviewed coverage map is `ci/ci-coverage.json`. It maps every responsibility
 from the former 13 workflows to the required gate, the non-routine release
@@ -107,8 +107,8 @@ cargo clean --target-dir target/release-gate
 
 ## Non-routine release gate
 
-The Rust `release-gate` command owns clean MSRV and portable cross-target
-checks, benchmark compilation, the 16-cycle resource soak, all 16 source
+The Rust `release-gate` command owns portable cross-target checks, benchmark
+compilation, the 16-cycle resource soak, all 16 source
 packages, release binaries, native artifact inspection, and the aggregate
 release-candidate audit. Reference C# performance regeneration and live-grid,
 physical-audio, proprietary-service, signing, and platform-native installer