Mk/bsd.ruby.mk: Bump RUBY_PORTREVISION of Ruby 2.7 and 3.0

Both lang/ruby27 and lang/ruby30 need to be rebuilt after default
version of Ruby has switched from 2.7 to 3.0.

Reported by: bdrewery
Fixes: eca58e376812 (Mk/bsd.default-versions.mk: Switch default version of Ruby from 2.7 to 3.0)