gh-112567: Add _Py_GetTicksPerSecond() function (#112587)

* Move _PyRuntimeState.time to _posixstate.ticks_per_second and
  time_module_state.ticks_per_second.
* Add time_module_state.clocks_per_second.
* Rename _PyTime_GetClockWithInfo() to py_clock().
* Rename _PyTime_GetProcessTimeWithInfo() to py_process_time().
* Add process_time_times() helper function, called by
  py_process_time().
* os.times() is now always built: no longer rely on HAVE_TIMES.