Add some pypy versions to CI building too

Author: mattsta

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ "3.10", "3.11", "3.12", "3.13" ]
+        python-version: [ "3.10", "3.11", "3.12", "3.13", "pypy3.10", "pypy3.11" ]
 
     steps:
       - uses: actions/checkout@v4