TST: change supported Python versions

Author: tacaswell

.github/workflows/testing.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.7', '3.8', '3.9', '3.10']
+        python-version: ['3.9', '3.10', '3.11', '3.12']
       fail-fast: false
     steps: