ignore others than v1.* tags (#2211)

Author: zetaab

cloudbuild.yaml

@@ -28,9 +28,10 @@ steps:
       # appropriately for the image before running make
       /buildx-entrypoint version
 
+      REALTAG=$(git describe --tags --always --dirty --match 'v1.*')
       make push-multiarch-images \
         REGISTRY=gcr.io/$PROJECT_ID \
-        VERSION=$_SHORT_TAG
+        VERSION=$REALTAG
 substitutions:
   # _GIT_TAG will be filled with a git-based tag for the image, of the form
   # vYYYYMMDD-hash, and can be used as a substitution