.github: test on 3.14 pre-release

Author: mrjbq7

.github/workflows/tests.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
     steps:
     - uses: actions/checkout@v3