MNT: add Python 3.14 to stable CI

Author: neutrinoceros

.github/workflows/ci.yml

@@ -23,16 +23,17 @@ jobs:
         - '3.11'
         - '3.12'
         - '3.13'
+        - '3.14'
         include:
           # only test oldest and most recent Python on other platforms
         - os: macos-latest
           python-version: '3.10'
         - os: macos-latest
-          python-version: '3.13'
+          python-version: '3.14'
         - os: windows-latest
           python-version: '3.10'
         - os: windows-latest
-          python-version: '3.13'
+          python-version: '3.14'
         - os: ubuntu-22.04
           python-version: 3.10.0
           # 2023-09-15 is numpy 1.26.0's release date