test on 3.13

Author: graingert

.github/workflows/main.yml

@@ -21,6 +21,7 @@ jobs:
           - "3.10"
           - "3.11"
           - "3.12"
+          - "3.13"
           - "pypy-3.8"
           - "pypy-3.9"
           - "pypy-3.10"
@@ -48,6 +49,7 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
           cache: pip
+          allow-prereleases: true
 
       - name: Install project dependencies
         run: |