Use specific py3.15 version

Author: JessicaTegner

.github/workflows/ci.yaml

@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-22.04, ubuntu-24.04, macos-15, macos-14, windows-2022]
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.15", "pypy3.9", "pypy3.10", ]
+        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "3.15.0-alpha.1", "pypy3.9", "pypy3.10", ]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Check out repository