Allow the GHA to report the unit tests results

See:
https://github.com/DOMjudge/domjudge/actions/runs/12247242151/job/34164708661?pr=2879

Here the push from dependabot failed to add the check-run results. Other
possible permissions:
https://docs.github.com/en/rest/checks/runs?apiVersion=2022-11-28#create-a-check-run

.github/workflows/unit-tests.yml

@@ -18,6 +18,8 @@ jobs:
         run: diff newcodecov .github/jobs/uploadcodecov.sh
 
   unit-tests:
+    permissions:
+      checks: write
     runs-on: ubuntu-24.04
     timeout-minutes: 20
     container:
@@ -79,3 +81,13 @@ jobs:
             /opt/domjudge/domserver/webapp/var/log/*.log
             /tmp/docker-logs
             /tmp/artifacts
+
+  event_file:
+    name: "Post results assuming forks"
+    runs-on: ubuntu-latest
+    steps:
+      - name: Upload
+        uses: actions/upload-artifact@v4
+        with:
+          name: Event File
+          path: ${{ github.event_path }}

.github/workflows/upload-unit-tests.yml

@@ -0,0 +1,34 @@
+name: Publish Unittest Results
+
+on:
+  workflow_run:
+    workflows: ["Unit tests"]
+    types:
+      - completed
+    permissions: {}
+
+  jobs:
+    test-results:
+       name: Test Results
+       runs-on: ubuntu-latest
+       if: github.event.workflow_run.conclusion != 'skipped'
+       permissions:
+         # required by download step to access artifacts API
+         actions: read
+         # write the actual check-run
+         checks: write
+         # needed unless run with comment_mode: off
+         pull-requests: write
+       steps:
+         - name: Download and Extract Artifacts
+           uses: dawidd6/action-download-artifact@e7466d1a7587ed14867642c2ca74b5bcc1e19a2d
+           with:
+             run_id: ${{ github.event.workflow_run.id }}
+             path: artifacts
+         - name: Publish Test Results
+           uses: EnricoMi/publish-unit-test-result-action@v2
+           with:
+             commit: ${{ github.event.workflow_run.head_sha }}
+             event_file: artifacts/Event File/event.json
+             event_name: ${{ github.event.workflow_run.event }}
+             files: "tmp/artifacts/**/*.xml"