Remove focal/Ubuntu 20.04 LTS from autoconf check.

Author: meisterT

.github/workflows/autoconf-check.yml

@@ -10,7 +10,7 @@ jobs:
   debian-family:
     strategy:
       matrix:
-        version: [jammy, focal, rolling]
+        version: [jammy, rolling]
         os: [ubuntu]
         releaseBranch:
           - ${{ contains(github.ref, 'gh-readonly-queue') }}