ci: make tests less parallel (#168)

Author: ascorbic

.github/workflows/test-e2e.yml

@@ -12,8 +12,8 @@ env:
   NEXT_REPO: vercel/next.js
   NEXT_TEST_MODE: deploy
   NEXT_JUNIT_TEST_REPORT: true
-  TEST_CONCURRENCY: 8
-  NEXT_E2E_TEST_TIMEOUT: 600000
+  TEST_CONCURRENCY: 2
+  NEXT_E2E_TEST_TIMEOUT: 300000
   NEXT_TELEMETRY_DISABLED: 1
   NEXT_SKIP_NATIVE_POSTINSTALL: 1
   TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
@@ -28,14 +28,13 @@ jobs:
     if:
       ${{ github.event_name == ('workflow_dispatch' || 'workflow_call') ||
       contains(github.event.pull_request.labels.*.name, 'run-e2e-tests') }}
-    name: Test group ${{ matrix.group }}/24
+    name: Test group ${{ matrix.group }}/12
     runs-on: ubuntu-latest
     timeout-minutes: 120
     strategy:
       fail-fast: false
       matrix:
-        group:
-          [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]
+        group: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
 
     steps:
       - name: Get Latest Next.js Release
@@ -132,7 +131,7 @@ jobs:
         env:
           NODE_ENV: production
           NEXT_EXTERNAL_TESTS_FILTERS: ../next-runtime-minimal/tests/netlify-e2e.json
-        run: node run-tests.js -g ${{ matrix.group }}/24 -c ${TEST_CONCURRENCY} --type e2e
+        run: node run-tests.js -g ${{ matrix.group }}/12 -c ${TEST_CONCURRENCY} --type e2e
         working-directory: ${{ env.next-path }}
 
       - name: Upload Test Results