update testing to use newer version of ubuntu

Author: djm21

.github/workflows/build-test-deploy.yml

@@ -22,8 +22,7 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.8', '3.9', '3.10', '3.11']
-        os-version: ['ubuntu-20.04', 'windows-latest', 'macos-latest']
-# Pinned Ubuntu version to 20.04 since no Python 3.6 builds available on ubuntu-latest (22.04) as of 2022-12-7.
+        os-version: ['ubuntu-latest', 'windows-latest', 'macos-latest']
 #        os-version: [ubuntu-latest, windows-latest, macos-latest]
 
     steps: