gha: update distros and version to install

- updating the "version" to install to 20.10 (previous version)
- remove ubuntu 18.04, as it's EOL soon
- add last 2 LTS versions of Ubuntu
- add centos:9 (stream)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

.github/workflows/ci.yml

@@ -9,10 +9,12 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu:18.04
+          - ubuntu:20.04
+          - ubuntu:22.04
           - centos:7
+          - quay.io/centos/centos:stream9
         version:
-          - 19.03
+          - "20.10"
           - ""
 
     steps: