Replace pypy3.9 with pypy3.10 in pytest (#567)

Author: dongwook-chan

.github/workflows/pytest.yml

@@ -14,7 +14,7 @@ jobs:
           - {name: 'CPython 3.7', python: '3.7'}
           - {name: 'CPython 3.11', python: '3.11'}
           - {name: 'Pypy 3.7', python: 'pypy-3.7'}
-          - {name: 'Pypy 3.9', python: 'pypy-3.9'}
+          - {name: 'Pypy 3.10', python: 'pypy-3.10'}
     name: ${{ matrix.name }}
     runs-on: ubuntu-latest
     timeout-minutes: 3