Update GitHub App authentication step to use APP_ID secret

Author: In-Ko

.github/workflows/get-project-column-ids.yml

@@ -18,7 +18,7 @@ jobs:
         id: auth
         uses: tibdex/github-app-token@v1
         with:
-          app_id: ${{ secrets.GITHUB_APP_ID }}
+          app_id: ${{ secrets.APP_ID }}
           private_key: ${{ secrets.PRIVATE_KEY }}
           installation_id: ${{ secrets.INSTALLATION_ID }}