[New msys2-runtime-package version] msys2-runtime: Avoid deadlocks with app execution aliases (#6736) #6444

msys2-runtime: Avoid deadlocks with app execution aliases (#6736)

https://github.com/msys2/msys2-runtime/issues/372 reports that calling `winget.exe` through its app execution alias from an interactive MSYS2 shell can leave the shell hanging after `winget.exe` exits. This affects all app execution aliases, not only `winget.exe`.

App execution alias handling was introduced in 0631c6644e (Cygwin: Treat Windows Store's "app execution aliases" as symbolic links, 2021-03-22), and 6c3d26961d (Cygwin: termios: Handle app execution alias in is_console_app(), 2025-12-10) taught `is_console_app()` to follow aliases using another `path_conv`, which allocates cygheap memory.

618eb90fc2 (Cygwin: console: Fix undesired mode change at exit of non-cygwin apps, 2026-09-19) added a second `is_console_app()` call from `wait_for_resume_if_necessary()`. Unfortunately, at that point, `child_info_spawn::worker()` already holds the non-recursive `cygheap_protect`, so following an alias tries to acquire the same lock recursively and deadlocks.

Let's avoid running `is_console_app()` under that lock by instead classifying the executable _once_, in `spawn_worker::setup()`, before acquiring the cygheap lock, then cache and reuse the result for both PTY setup and the post-resume wait.

This addresses https://github.com/msys2/msys2-runtime/issues/372

This corresponds to https://github.com/msys2/msys2-runtime/pull/373