Skip external help integration from forks

PRs from forks do not have access to the help repo.

.github/workflows/code-scanning-pack-gen.yml

@@ -80,6 +80,8 @@ jobs:
 
       - name: Checkout external help files
         id: checkout-external-help-files
+        # Forks do not have access to an appropriate token for the help files
+        if: !github.event.pull_request.head.repo.fork
         uses: actions/checkout@v4
         with:
           ssh-key: ${{ secrets.CODEQL_CODING_STANDARDS_HELP_KEY }}
@@ -88,7 +90,7 @@ jobs:
           path: external-help-files
 
       - name: Include external help files
-        if: steps.checkout-external-help-files.outcome == 'success'
+        if: !github.event.pull_request.head.repo.fork && steps.checkout-external-help-files.outcome == 'success'
         run: |
           pushd external-help-files
           find . -name '*.md' -exec rsync -av --relative {} "$GITHUB_WORKSPACE" \;