gh-111482: Use Argument Clinic for clock_gettime() (#111641)

Use Argument Clinic for time.clock_gettime() and
time.clock_gettime_ns() functions.

Benchmark on time.clock_gettime_ns():

    import time
    import pyperf
    runner = pyperf.Runner()
    runner.timeit(
        'clock_gettime_ns(CLOCK_MONOTONIC_COARSE)',
        setup='import time; clock_gettime_ns=time.clock_gettime_ns; CLOCK_MONOTONIC_COARSE=6',
        stmt='clock_gettime_ns(CLOCK_MONOTONIC_COARSE)')

Result on Linux with CPU isolation:

Mean +- std dev: [ref] 134 ns +- 1 ns -> [change] 55.7 ns +- 1.4 ns: 2.41x faster