Iron Golem

• WOTC Official Reminder Textofficial rules
  Vigilance — Attacking doesn't cause this creature to tap.

• WWizards of the Coast2021-07-23
  Official Ruling
  If the Iron Golem can't attack or block for any reason (such as being tapped), then it doesn't attack or block. If there's a cost associated with having it attack or block, its controller isn't forced to pay that cost, so it doesn't have to attack or block in that case either.

Rulings via Scryfall