Fix trying to push to main branch

.github/workflows/update-from-changelog.yml

@@ -5,7 +5,6 @@ on:
     workflows: ["Update From Submodule"]
     types:
       - completed
-  workflow_dispatch:
 
 permissions:
   contents: write
@@ -18,14 +17,15 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
+          # Check out the branch from the triggering workflow
+          ref: ${{ github.event.workflow_run.head_branch }}
           submodules: true
 
-      - name: Validate branch
+      - name: Validate repository
         run: |
-          BRANCH_NAME="${{ github.ref_name }}"
-          echo "Branch: $BRANCH_NAME"
-          if [[ "$BRANCH_NAME" != "main" ]]; then
-            echo "Not on main branch. Exiting."
+          REPO_NAME="${{ github.event.workflow_run.head_repository.full_name }}"
+          if [[ $REPO_NAME != "${{ github.repository }}" ]]; then
+            echo "Untrusted repository detected! Exiting."
             exit 1
           fi