Log Message:
graphics/ruby-RMagick: update to 4.2.1

RMagick 4.2.1 (2021-02-08)

Bug Fixes:
* Fix compilation with optimization on glibc (#1263)

RMagick 4.2.0 (2021-02-05)

Improvements:

* Updated error messages if runtime ImageMagick version was not matched
  with when installed rmagick (#1213)
* Improve Image#resize performance with ImageMagick 7 (#1240)
* Added new colorspaces (#1252)

Bug Fixes:

* Fix assertion failed in Magick::TextureFill.new with with unexpected
  argument (#1216)
* Call with yield when there is a block arguments (#701)
* Avoid crash with monitor feature on Ruby 3.0 (#1253)