ubuntu 20.04 --> 22.04

Author: lelandaisb

.github/workflows/spack-ubuntu.yml

@@ -14,7 +14,7 @@ jobs:
     # well on Linux, Windows or Mac.
     runs-on: ubuntu-latest
     container:
-      image: lihpccg/mgx-ubuntu.20.04-spack.0.19.0:latest
+      image: lihpccg/mgx-ubuntu.22.04-spack.0.19.0:latest
     strategy:
       fail-fast: false
       matrix: