-Update CI

Author: thebigG

.github/workflows/ci_container.yaml

@@ -19,7 +19,7 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - { name: "ubuntu-18.04", os: "ubuntu-18.04" }
+          - { name: "ubuntu-20.04", os: "ubuntu-20.04" }
     name: build-container-linux
     runs-on: ${{ matrix.config.os }}
     steps: