ci: fix refs

Author: carsakiller

.github/workflows/metadata.yml

@@ -27,10 +27,7 @@ jobs:
 
       - name: Detect Added Submodules
         run: |
-          BASE_REF=${{ github.event.pull_request.base.sha }}
-          HEAD_REF=${{ github.event.pull_request.head.sha }}
-
-          ADDED_SUBMODULES=$(git diff --submodule ${BASE_REF}..${HEAD_REF} | grep '^Submodule' | awk '{ print $2 }')
+          ADDED_SUBMODULES=$(git diff --submodule main..head | grep '^Submodule' | awk '{ print $2 }')
           echo "Added submodules: $ADDED_SUBMODULES"
           echo "ADDED_SUBMODULES=$ADDED_SUBMODULES" >> $GITHUB_ENV