fix release branch tagging

.github/actions/bump-version/action.yaml

@@ -38,6 +38,13 @@ runs:
       id: bump
       shell: bash
       run: |
+        EXISTING_TAG="$(git tag --points-at HEAD "v*" | head -n 1)"
+        if [ -n "${EXISTING_TAG}" ]; then
+          echo "Tag ${EXISTING_TAG} already points at this commit; skipping bump."
+          echo "tag=${EXISTING_TAG}" >> "${GITHUB_OUTPUT}"
+          exit 0
+        fi
+
         REF="${GITHUB_REF:-${GITEA_REF}}"
         BRANCH="${REF#refs/heads/}"
         git fetch origin "${BRANCH}" --tags
@@ -69,8 +76,18 @@ runs:
             BUMP_CMD="npm version prerelease --preid=dev --no-git-tag-version"
             ;;
           release*)
-            npm version prerelease --preid=rc-${BRANCH_SAFE} --no-git-tag-version
-            BUMP_CMD="npm version prerelease --preid=rc-${BRANCH_SAFE} --no-git-tag-version"
+            RELEASE_VERSION=""
+            if [[ "${BRANCH}" =~ ^release/v?([0-9]+\.[0-9]+\.[0-9]+)$ ]]; then
+              RELEASE_VERSION="${BASH_REMATCH[1]}"
+            fi
+
+            if [[ -n "${RELEASE_VERSION}" ]]; then
+              npm version "${RELEASE_VERSION}-rc.0" --no-git-tag-version --allow-same-version
+              BUMP_CMD="npm version prerelease --preid=rc --no-git-tag-version"
+            else
+              npm version prerelease --preid=rc-${BRANCH_SAFE} --no-git-tag-version
+              BUMP_CMD="npm version prerelease --preid=rc-${BRANCH_SAFE} --no-git-tag-version"
+            fi
             ;;
           *)
             npm version prerelease --preid=nightly-${BRANCH_SAFE} --no-git-tag-version