Stop using Ubuntu Focal runners

Author: Alex-Welsh

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   pre-commit:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Check out the codebase.
         uses: actions/checkout@v3
@@ -32,7 +32,7 @@ jobs:
         run: pre-commit run --all-files
 
   bash-unit-tests:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Check out the codebase.
         uses: actions/checkout@v3