[Feature Request] Allow configuring path of `buck-out` directory

Currently, Buck2 creates the `buck-out` directory at the root of the repository.
And there doesn't appear to be a way to **configure** this path.

I would appreciate it if there could be an option that allows specifying a custom path for the `buck-out` directory.

In my use case, where the code directory is mounted as read-only, it's not possible to write to this directory within the repository itself.
As a result, I need the ability to specify a custom path for `buck-out` outside of the repository.

This could be implemented through either:
- A configuration option in `.buckconfig`
- A command-line parameter

This would allow better flexibility and integration with systems where the code repository