Update workflows to use ubuntu-latest

Author: iarspider

Diff for: .github/workflows/test-changes.yaml

@@ -8,7 +8,7 @@ on:
       - master
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         python-version: [ '3.x' ]

Diff for: .github/workflows/test-process-pr.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         python-version: ["3.6", "3.9", "3.10", "3.11", "3.12"]