add PyPy 3.11 to build matrix

Author: xflr6

.github/workflows/build.yaml

@@ -21,6 +21,8 @@ jobs:
             os: ubuntu-latest
           - python-version: "3.10"
             os: ubuntu-latest
+          - python-version: pypy-3.11
+            os: ubuntu-latest
           - python-version: pypy-3.10
             os: ubuntu-latest
     steps: