GHA: Test Python 3.14 (#133)

Author: vstinner

.github/workflows/build.yml

@@ -26,9 +26,10 @@ jobs:
           - "3.10"
           - "3.11"
           - "3.12"
-          # CPython 3.13 final is scheduled for October 2024:
-          # https://peps.python.org/pep-0719/
           - "3.13"
+          # CPython 3.14 final is scheduled for October 2025:
+          # https://peps.python.org/pep-0719/
+          - "3.14"
 
           # PyPy versions:
           # - https://github.com/actions/setup-python/blob/main/docs/advanced-usage.md