ghostscript @9.19: update to 9.21

[MarcusCalhoun-Lopez (Marcus Calhoun-Lopez)]

In 947d9823ca5dbb38be98ae5730e725f7af787693/macports-ports:

ghostscript: update version 9.19->9.21

Fixes #53805

[ryandesign (Ryan Carsten Schmidt)]

This changed the install_name of libgs.dylib, so all ports that link to that library need to be revbumped. Before you do that, you need to fix it so that libgs.dylib gets the correct install_name again (with the full path to the library); see #54019.

[neverpanic (Clemens Lang)]

In fd91a5d970954bd66ae88e47adeb8d1daa8cfbe5/macports-ports:

Revbump library users of ghostscript

After the ghostscript update in 947d9823ca, the install name of the
ghostscript library changed. All dependents need to be rebuilt against
the new libgs.dylib, so revbump them.

This list has been generated using 'port echo depends:ghostscript'.
I have manually excluded ports that only had a runtime dependency (as
opposed to a library dependency), assuming they would only need the
binary. I have also excluded ports with library dependencies that only
seem to use the 'gs' binary (e.g. because they declare
depends_skip_archcheck for ghostscript).

See: #53805
See: #54019