devel/gearmand-devel: Remove port from tree

Unmaintained, obsolete and hasn't compiled for over half a year.

References:
https://www.freshports.org/devel/gearmand-devel/
https://portsfallout.com/fallout?port=devel%2Fgearmand-devel$
https://github.com/gearman/gearmand

PR: 255210
Reported by: daniel.engberg.lists@pyret.net