Fail fast if e2e tests if PR is from fork. (#2706)

* Fail fast if e2e tests if PR is from fork.

* this

* this

* this

* this

* boop

* this

Author: sobolk

.github/workflows/health_checks.yml

@@ -324,7 +324,9 @@ jobs:
           cdk-lib-version: ${{ needs.resolve_inputs.outputs.cdk_lib_version }}
       - name: Check if any E2E tests should run
         id: check
-        run: echo "run_e2e=$(npx tsx scripts/do_include_e2e.ts)" >> "$GITHUB_OUTPUT"
+        run: |
+          run_e2e=$(npx tsx scripts/do_include_e2e.ts)
+          echo "run_e2e=$run_e2e" >> "$GITHUB_OUTPUT"
       - run: echo run_e2e set to ${{ steps.check.outputs.run_e2e }}
       - name: Check if Package Manager E2E tests should be included
         id: check_package_manager

scripts/do_include_e2e.ts

@@ -17,6 +17,16 @@ const prHasRunE2ELabel = async () => {
   const hasRunE2ELabel = prInfo.labels.some(
     (label) => label.name === 'run-e2e',
   );
+
+  if (
+    hasRunE2ELabel &&
+    prInfo.head?.repo?.full_name !== 'aws-amplify/amplify-backend'
+  ) {
+    throw new Error(
+      'PR must be opened from a branch in aws-amplify/amplify-backend repository when running e2e tests.',
+    );
+  }
+
   return hasRunE2ELabel;
 };