Disable Ubuntu 20.04 based parsing in the CI

Author: mcserep

.github/workflows/ci.yml

@@ -182,7 +182,7 @@ jobs:
     strategy:
       matrix:
         db: [postgresql, sqlite3]
-        os: [ubuntu-20.04, ubuntu-22.04]
+        os: [ubuntu-22.04] # ubuntu-20.04
       fail-fast: false
 
     runs-on: ${{ matrix.os }}