ci(fix): Fix docker-release workflow (#2260)

Signed-off-by: Dave Henderson <[email protected]>

.github/workflows/docker-release.yml

@@ -46,6 +46,8 @@ jobs:
 
         set -x
         export repo=${srcrepo}
+        export git_tag=${TAG_NAME}
+        export major_version=${git_tag%\.*}
         docker buildx imagetools create -t ${repo}:stable ${srcrepo}:latest
         docker buildx imagetools create -t ${repo}:${git_tag} ${srcrepo}:latest
         docker buildx imagetools create -t ${repo}:${major_version} ${srcrepo}:latest