Move Unreal engine job as well

Author: jdetter

.github/workflows/ci.yml

@@ -292,7 +292,7 @@ jobs:
     name: Unreal Engine Tests
     # This can't go on e.g. ubuntu-latest because that runner runs out of disk space. ChatGPT suggested that the general solution tends to be to use
     # a custom runner.
-    runs-on: spacetimedb-runner
+    runs-on: spacetimedb-new-runner
     # Skip if this is an external contribution. GitHub secrets will be empty, so the step would fail anyway.
     if: ${{ github.event_name != 'pull_request' || !github.event.pull_request.head.repo.fork }}
     container: