Update tox CI to use python 3.10

Author: Alex-Welsh

.github/workflows/stackhpc-pull-request.yml

@@ -9,17 +9,17 @@ name: Pull request
   pull_request:
 jobs:
   tox:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     permissions: {}
     strategy:
       matrix:
         include:
           - environment: pep8
-            python-version: 3.8
+            python-version: "3.10"
           - environment: releasenotes
-            python-version: 3.8
+            python-version: "3.10"
           - environment: docs
-            python-version: 3.8
+            python-version: "3.10"
     name: Tox ${{ matrix.environment }} with Python ${{ matrix.python-version }}
     if: github.repository == 'stackhpc/stackhpc-kayobe-config'
     steps: