CI: Fix runs-on: field in update-version.yaml

Author: DeeDeeG

.github/workflows/update-version.yaml

@@ -7,7 +7,7 @@ on:
 jobs:
   update_docs:
     if: contains(github.event.issue.labels.*.name, 'update-version')
-    runs-on: ubuntu
+    runs-on: ubuntu-latest
     permissions:
       contents: write
       pull-requests: write