Update CI configuration to use ubuntu-latest for build and deploy jobs

Author: dvershinin

.github/workflows/pythonpackage.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       max-parallel: 4
       matrix:

.github/workflows/pythonpublish.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   deploy:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
     - name: Set up Python