Attempt to fix CI

Author: niconoe

.github/workflows/run-unit-tests.yml

@@ -6,7 +6,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12', 'pypy-3.8' ]
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12', 'pypy-3.9' ]
         exclude: # Python < v3.8 does not support Apple Silicon ARM64.
           - python-version: "3.7"
             os: macos-latest