*/*: Cleanup after removal of lang/ruby26

• Remove conditions that are applied to Ruby 2.6 or before.
• Remove BROKEN_RUBY26.
• Mark ports broken with all supported versions of Ruby as DEPRECATED and set EXPIRATION_DATE.

Reviewed by: rene
Approved by: rene (portmgr)
Differential Revision: https://reviews.freebsd.org/D34745