fix(ci): improve cypress parallelization

.github/workflows/test.yml

@@ -277,11 +277,24 @@ jobs:
           name: frontend_dist
           path: ./frontend/dist
 
+  # Workaround for this old issue, still not fixed:
+  # https://github.com/cypress-io/github-action/issues/121
+  define-frontend-e2e-batches:
+    runs-on: ubuntu-latest
+    outputs: 
+      batches: ${{ steps.get-batches.outputs.batches }}
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - name: Get spec batches
+        id: get-batches
+        run: echo "batches=$(find frontend/cypress/e2e -type f -name '*.spec.ts' -printf "%P\n" | jq -R . | jq -cs .)" >> "$GITHUB_OUTPUT"
+
   test-frontend-e2e:
     runs-on: ubuntu-latest
     needs:
       - api-build
       - build-frontend
+      - define-frontend-e2e-batches
     strategy:
       # when one test fails, DO NOT cancel the other
       # containers, because this will kill Cypress processes
@@ -289,7 +302,7 @@ jobs:
       # https://github.com/cypress-io/github-action/issues/48
       fail-fast: false
       matrix:
-        containers: [1, 2, 3, 4, 5]
+        spec: ${{ fromJSON(needs.define-frontend-e2e-batches.outputs.batches) }}
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
       - name: Download Vikunja Binary
@@ -318,7 +331,7 @@ jobs:
           working-directory: frontend
           browser: chrome
           record: true
-          parallel: true
+          spec: cypress/e2e/${{ matrix.spec }}
           start: |
             pnpm run preview
           wait-on: http://127.0.0.1:4173,http://127.0.0.1:3456/api/v1/info
@@ -329,3 +342,12 @@ jobs:
           CYPRESS_API_URL: http://127.0.0.1:3456/api/v1
           CYPRESS_TEST_SECRET: averyLongSecretToSe33dtheDB
           CYPRESS_DEFAULT_COMMAND_TIMEOUT: 60000
+  
+  # This step only exists so that we can make it required, because we can't make 
+  # the actual test step required due to the matrix
+  test-frontend-e2e-success:
+    runs-on: ubuntu-latest
+    needs:
+      - test-frontend-e2e
+    steps:
+      - run: exit 0