fix RELEASE_TAG

Signed-off-by: Ayato Tachibana <[email protected]>

.github/workflows/publish-multiarch-image.yaml

@@ -28,7 +28,7 @@ jobs:
           set -xue
           # Target version must match major.minor.patch and optional -rcX suffix
           # where X must be a number.
-          TARGET_VERSION=${SOURCE_TAG#*v}
+          TARGET_VERSION=${SOURCE_TAG#refs/tags/v}
           if ! echo "${TARGET_VERSION}" | egrep '^[0-9]+\.[0-9]+\.[0-9]+(-rc[0-9]+)*$'; then
             echo "::error::Target version '${TARGET_VERSION}' is malformed, refusing to continue." >&2
             exit 1
@@ -39,7 +39,7 @@ jobs:
           TARGET_BRANCH="release-${TARGET_VERSION%\.[0-9]*}"
 
           # The release tag is the source tag
-          RELEASE_TAG="${SOURCE_TAG}"
+          RELEASE_TAG="${SOURCE_TAG#refs/tags/}"
 
           # Make the variables available in follow-up steps
           echo "TARGET_VERSION=${TARGET_VERSION}" >> $GITHUB_ENV