Revert "t/openxr: Use XRT_MODULE_IPC to decide if we do IPC build or not"
This resulted in "in process" builds actually defaulting to building
IPC clients without the server, breaking them for most users.
This reverts commit cc2fa1ea532aaeb838b9f41bf200e21b000e96af.
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2410>
authored by