gh-120158: Fix inconsistent monitoring state when setting events too frequently (gh-141845)

If we overflowed the global version counter (i.e., after 2*24 calls to
`_PyMonitoring_SetEvents`), we bailed out after setting global monitoring
events but before instrumenting code objects, which led to assertion errors
later on.

Also add a `time.sleep()` to `test_free_threading.test_monitoring` to avoid
overflowing the global version counter.