Route vX.Y.Z-rc.N tags to the beta track, not stable

release.yml matches v*, which would have published an RC into the
stable bakery index and pointed latest at it. Skip any tag whose name
contains -rc there, and fire beta-release.yml on v*-rc.* instead.

.forgejo/workflows/release.yml

@@ -6,6 +6,9 @@ on:
 
 jobs:
   build:
+    # RC tags are `v*` too (`v0.1.1-rc.1`) — those belong on the beta
+    # track, see beta-release.yml. A stable cut is a plain `vX.Y.Z`.
+    if: ${{ !contains(github.ref_name, '-rc') }}
     runs-on: [self-hosted, hestia]
     steps:
       - name: checkout