FindCUDAToolkit: Add nvptxcompiler_static dependency on Threads::Threads

As brought up here: #23892 (comment 1268311) the nvptxcompiler_static.a uses symbols defined in Threads::Threads.

Verified locally with:

nm libnvptxcompiler_static.a | grep pthread
                 U pthread_attr_destroy
                 U pthread_attr_init
                 U pthread_attr_setdetachstate
                 U pthread_attr_setinheritsched
                 U pthread_attr_setschedparam
                 U pthread_attr_setschedpolicy
                 U pthread_attr_setstacksize
                 U pthread_cond_destroy
                 U pthread_cond_init
                 U pthread_cond_timedwait
                 U pthread_create
                 U pthread_exit
                 U pthread_getspecific
                 U pthread_join
                 U pthread_key_create
                 U pthread_key_delete
                 U pthread_kill
                 U pthread_mutexattr_destroy
                 U pthread_mutexattr_init
                 U pthread_mutexattr_settype
                 U pthread_mutex_destroy
                 U pthread_mutex_init
                 U pthread_mutex_lock
                 U pthread_mutex_unlock
                 U pthread_setspecific

Backport: release
Topic-rename: FindCUDAToolkit-nvptxcompiler-static-deps