maintainer-feedback requested: [Bug 283105] graphics/linux-rl9-gdk-pixbuf2 is jasper-libs an unneeded dependency?

Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-emulation (Nobody)
<emulation@FreeBSD.org> for maintainer-feedback:
Bug 283105: graphics/linux-rl9-gdk-pixbuf2 is jasper-libs an unneeded
dependency?
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=283105



--- Description ---
https://gitlab.gnome.org/GNOME/gdk-pixbuf/-/blob/2.42.8/NEWS states that 2.42.0
removed libjasper JPEG2000 loader and the nonlinux port no longer depends on
jasper-libs when it went from version 2.40.0 to 2.42.8. I thought this may be
debris if the c7 port was modified into an updated rl9 port without
re-reviewing what the actual dependencies are but would like to know if there
is a proper way to confirm when something is a needed dependency, only
dynamically needed, or is unrelated? I'd presume such a step would be helpful
for port maintainers to watch out for including something that is no longer
needed after a port is updated in general too but if there are different/better
steps to that it would be appreciated too.

I ran across this with unrelated work of manually removing dependencies on
games/linux-dwarffortress and found that it still launched without the
linux-c7-jasper-libs which is brought in by linux-c7-gdk-pixbuf2. There were
similarly other ports that are either unneeded dependencies of dependencies
with some being only sometimes needed depending on dwarffortress's settings.
Only a few were direct dependencies and dynamically loaded which I assume could
be shifted off to a port option. I presume that unless it is a direct
dependency or an accidentally included but unneeded dependency of the
dependency then it can be fixed but that others would get included with no
clean solution to skip them.