The GitHub actions macOS 13 runner is being shutdown later this fall as noted in this blog post [1].

The JavaFX GHA builds currently use macOS 13 as the way to run macOS / x64 builds. As noted in the blog post, we need to update our GHA scripts to use the macos-15-intel runner instead.

Note that the GitHub macos-15 runners have Xcode 16.0 as the minimum version of Xcode rather than the Xcode 15.4 that we use in production. This is fine, and has the added benefit of early detection if we introduce any Xcode 16 bugs. We will continue to run macOS / aarch64 builds using the macos-14 runner with Xcode 15.4.

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