ci: do not sync master branch

.github/workflows/git_sync.yaml

@@ -3,7 +3,6 @@ name: Sync to enterprise
 on:
   push:
     branches:
-      - master
       - main-v*
 
 jobs:
@@ -23,11 +22,7 @@ jobs:
         id: create_pull_request
         run: |
           set -euo pipefail
-          if [ "$GITHUB_REF" = "refs/heads/master" ]; then
-            EE_REF="refs/heads/enterprise"
-          else
-            EE_REF="${GITHUB_REF}-enterprise"
-          fi
+          EE_REF="${GITHUB_REF}-enterprise"
           R=$(curl --silent --show-error \
             -H "Accept: application/vnd.github.v3+json" \
             -H "Authorization: token ${{ secrets.CI_GIT_TOKEN }}" \