Change PHP default version to 8.0

- databases/xapian-bindings is a mata port which do not have
  php:flavors and is unable to be MARKED to IGNORE as one of it's
  dependent databases/php-xapian do not support php8.0. Hence this
  creates a circular dependency and it fails to start bulk building. So
  for now remove PHP from OPTIONS_DEFAULT.

PR:             260595
Approved by:	ale portmgr(exp-run)
Sponsored by:	Bounce Experts