Changed CI to just run on ubuntu-latest

If we already have to bump this version as GitHub phases out older
Ubuntu runners (which is reasonable), I don't really see the value of
pinning a specific version. We might as well just respond to any
broken dependencies caused by GitHub's implicit updates as they
happen...

It's not like CI is truly continuous.

.github/workflows/status.yml

@@ -11,7 +11,7 @@ defaults:
 jobs:
   # forward custom statuses
   status:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: dawidd6/action-download-artifact@v2
         continue-on-error: true
@@ -60,7 +60,7 @@ jobs:
 
   # forward custom pr-comments
   comment:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     # only run on success (we don't want garbage comments!)
     if: ${{github.event.workflow_run.conclusion == 'success'}}