bug#75471: perl-gtk2 Failing Tests

[Andrew Wong via Bug reports for GNU Guix <bug-guix@gnu.org>]

It appears that the perl-gtk2 package is failing to build due to broken 
tests:

phase `build' succeeded after 11.5 seconds
starting phase `check'
"/gnu/store/v6bivyjbg6bj07s8iqfzdm6hpvypc0p1-perl-5.36.0/bin/perl" 
-MExtUtils::Command::MM -e 'cp_nonempty' -- Gtk2.bs 
blib/arch/auto/Gtk2/Gtk2.bs 644
PERL_DL_NONLAZY=1 
"/gnu/store/v6bivyjbg6bj07s8iqfzdm6hpvypc0p1-perl-5.36.0/bin/perl" 
"-MExtUtils::Command::MM" "-MTest::Harness" "-e" "undef 
*Test::Harness::Switches; test_harness(0, 'blib/lib', 'blib/arch')" t/*.t
# Testing Gtk2 1.24993
#    Running against gtk+ 2.24.33
#   Compiled against gtk+ 2.24.33
t/00.Gtk2.t ........................ ok
---8<---
t/GdkPango.t ....................... skipped: Gtk2->init_check failed, 
probably unable to open DISPLAY
Wide character in subroutine entry at t/GdkPixbuf.t line 17.
Couldn’t recognize the image file format for file 
“gtk-demo/floppybuddy.gif” at t/GdkPixbuf.t line 17.
# Looks like your test exited with 2 before it could output anything.
t/GdkPixbuf.t ......................
Dubious, test returned 2 (wstat 512, 0x200)
Failed 111/111 subtests
Unrecognized image file format at t/GdkPixbufLoader.t line 46.
# Looks like your test exited with 2 before it could output anything.
t/GdkPixbufLoader.t ................
Dubious, test returned 2 (wstat 512, 0x200)
Failed 29/29 subtests
t/GdkPixbufSimpleAnim.t ............ ok
---8<---

This is not the first time, see bug#38521. Also see the build farm 
report https://ci.guix.gnu.org/build/8217599/details