create experimental branch first

Author: tatomyr

.github/workflows/experimental-pr.yaml

@@ -17,6 +17,10 @@ jobs:
         uses: actions/checkout@v4
         with:
           ref: ${{ github.event.pull_request.head.ref }}
+          fetch-depth: 0
+
+      - name: Create/Update the experimental branch from main
+        run: git push -f origin main:refs/heads/experimental
 
       - name: Create PR to experimental
         env: