Bump ubuntu version of release-test CI job

Signed-off-by: Steffen Jaeckel <[email protected]>

Author: sjaeckel

.github/workflows/main.yml

@@ -111,7 +111,7 @@ jobs:
           cat test-suite*.log || true
 
   release-test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     name: Check if release would work
     steps:
       - uses: actions/checkout@v2