Simplify token usage for submodule updates

Removed the option to use a Personal Access Token for submodule updates and simplified the token usage to only GITHUB_TOKEN.

Author: lmangani

.github/workflows/update-submodules.yml

@@ -22,12 +22,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           submodules: false
-          # SUBMODULE_UPDATE_PAT: a Personal Access Token (repo + workflow scopes)
-          # stored as a repository secret. Without it the GITHUB_TOKEN is used,
-          # but pushes made by GITHUB_TOKEN do NOT trigger CI workflows on the
-          # resulting PR. Create a PAT at Settings → Developer settings →
-          # Personal access tokens and add it at Settings → Secrets → Actions.
-          token: ${{ secrets.SUBMODULE_UPDATE_PAT || secrets.GITHUB_TOKEN }}
 
       - name: Update every submodule to remote HEAD
         id: update
@@ -46,7 +40,7 @@ jobs:
         if: steps.update.outputs.changed == 'true'
         uses: peter-evans/create-pull-request@v7
         with:
-          token: ${{ secrets.SUBMODULE_UPDATE_PAT || secrets.GITHUB_TOKEN }}
+          token: ${{ secrets.GITHUB_TOKEN }}
           commit-message: "chore: update submodules to latest HEAD"
           branch: chore/update-submodules
           delete-branch: true