ci: Lock Ubuntu version on 22.04

These workflows are failing due to `ubuntu-latest` being updated from version `22.04` to `24.04`.

Reference: https://github.com/actions/runner-images/issues/10636

Changelog-None.

.github/workflows/rdme-docs-sync.yml

@@ -10,7 +10,7 @@ on:
 
 jobs:
   rdme-docs-sync:  
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Check out repo 📚
         uses: actions/checkout@v4