Pin github workflow to Ubuntu 20.04 for now

Ubuntu 22.04 causes issues with libdbd-mariadb-perl, we cannot use the new OS image until this is resolved.

Author: drdrew42

.github/workflows/generate-opl-release.yml

@@ -11,7 +11,7 @@ on:
 
 jobs:
   release:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     permissions:
       contents: write