We have not checked for this KEYWORD for a long time now, so this
is a complete noop, and thus no PORTREVISION bump. Removing it at
this point is mostly for pedantic reasons, and partly to avoid
perpetuating this anachronism by copy and paste to future scripts.
Based on the patch provided with the PR, but the PREFIX is determined
at run time in the committed version.
PR: ports/56176
Submitted by: Kimura Fuyuki <fuyuki@nigredo.org>