Drop Python 3.8 tests

Author: dstansby

.github/workflows/test.yaml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
 
     steps: