update to 20.04

Author: CodeByDrescher

.github/workflows/validateCommitSimulator.yml

@@ -7,7 +7,7 @@ on:
 jobs:
   validateCommit:
     name: Validate and/or commit simulator
-    runs-on: ubuntu-latest # includes Docker
+    runs-on: ubuntu-20.04 # includes Docker
     if: |
       github.event.issue.state == 'open'
       && contains(github.event.issue.labels.*.name, 'Validate/submit simulator')