CI: Update CI to Python 3.14, add nightly builds.

Author: Robert Jackson

.github/workflows/python-package.yml

@@ -8,6 +8,8 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+  schedule:
+    - cron: '0 2 * * *'  # Runs at 2:00 AM UTC every day
 
 jobs:
   build:
@@ -20,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
         os: [macOS, ubuntu, Windows]
 
     steps: