build(dev): use macos-15 runners (#109)

Because [Macos-13 runner is about to go away][gh-notice].

[gh-notice]: https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/

Author: 2bndy5

.github/workflows/python.yml

@@ -131,9 +131,9 @@ jobs:
     strategy:
       matrix:
         platform:
-          - runner: macos-13
+          - runner: macos-15-intel
             target: x86_64
-          - runner: macos-14
+          - runner: macos-15
             target: aarch64
     steps:
       - uses: actions/checkout@v6