Prevent the github action to take forever.

Only apply this for the two actions that most likely can hang for now.
20mins should be plenty.

Author: meisterT

.github/workflows/integration.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   integration:
     runs-on: ubuntu-24.04
+    timeout-minutes: 20
     container:
       image: domjudge/gitlabci:24.04
       options: --privileged --cgroupns=host --init

.github/workflows/runpipe.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   runpipe:
     runs-on: ubuntu-24.04
+    timeout-minutes: 20
     container:
       image: domjudge/gitlabci:24.04
       options: --privileged --cgroupns=host --init