Migrate to publish-to-bcr Actions workflow

.github/workflows/publish-to-bcr.yaml

@@ -0,0 +1,25 @@
+name: Publish to BCR
+
+on:
+    release:
+        types: [published]
+    workflow_dispatch:
+        inputs:
+            tag_name:
+                required: true
+                type: string
+                description: 'The release tag to publish (e.g. v0.9.0)'
+
+jobs:
+    publish:
+        uses: bazel-contrib/publish-to-bcr/.github/workflows/publish.yaml@v1.5.0
+        with:
+            tag_name: ${{ inputs.tag_name || github.event.release.tag_name }}
+            registry_fork: benchsci/bazel-central-registry
+            attest: true
+        permissions:
+            contents: write
+            id-token: write
+            attestations: write
+        secrets:
+            publish_token: ${{ secrets.BCR_PUBLISH_TOKEN }}