reduce concurrency for default runner

Author: ijjk

.github/workflows/test-e2e-deploy.yml

@@ -128,4 +128,4 @@ jobs:
           IS_TURBOPACK_TEST: 1
           NEXT_TEST_JOB: 1
           NEXT_TELEMETRY_DISABLED: 1
-        run: node run-tests.js --timings -g ${{ matrix.group }} -c 2 --type e2e
+        run: node run-tests.js --timings -g ${{ matrix.group }} -c 1 --type e2e