Test Python 3.15 final (#446)

Author: hugovk

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
         - "3.12"
         - "3.13"
         - "3.14"
-        - "3.15-dev"
+        - "3.15"
     steps:
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
     - name: Set up Python ${{ matrix.python-version }}