Update nightly.yml

Author: lahirumaramba

.github/workflows/nightly.yml

@@ -54,7 +54,7 @@ jobs:
       run: dotnet test FirebaseAdmin/FirebaseAdmin.Tests
 
     - name: Run integration tests
-      run: ./.github/scripts/run_integration_tests
+      run: ./.github/scripts/run_integration_tests.sh
       env:
         FIREBASE_SERVICE_ACCT_KEY: ${{ secrets.FIREBASE_SERVICE_ACCT_KEY }}
         FIREBASE_API_KEY: ${{ secrets.FIREBASE_API_KEY }}