test: ubuntu-20.04 has been removed

Author: asmacdo

.github/workflows/base-tests.yaml

@@ -12,7 +12,7 @@ jobs:
       matrix:
         os:
           - macos-latest
-          - ubuntu-20.04
+          - ubuntu-latest
     steps:
       - name: Check out repository
         uses: actions/checkout@v4

.github/workflows/tests.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   tests:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
     steps: