Release 2023a - 2023-03-22 12:39:33 -0700

  Briefly:
    Egypt now uses DST again, from April through October.
    This year Morocco springs forward April 23, not April 30.
    Palestine delays the start of DST this year.
    Much of Greenland still uses DST from 2024 on.
    America/Yellowknife now links to America/Edmonton.
    tzselect can now use current time to help infer timezone.
    The code now defaults to C99 or later.
    Fix use of C23 attributes.