Get rid of manticore-buddy binary

[donhardman]

Proposal:

We should update the code to unify how we execute Manticore across platforms. Instead of calling manticore-buddy binary on Linux and using manticore-executor [buddy-path] on Windows, we should standardize to always use manticore-executor [buddy-path] from the system path, similar to how it's currently performed on Windows inside Docker.

The task is to unify the execution method and make Buddy run with manticore-executor [buddy-path] consistently across all platforms, replacing the current bin/manticore-buddy approach that we plan to remove.

Checklist:

^{To be completed by the assignee. Check off tasks that have been completed or are not applicable.}

• Implementation completed
• Tests developed
• Documentation updated
• Documentation reviewed
• Changelog updated
• OpenAPI YAML updated and issue created to rebuild clients