Failed to emerge with circular dependencies

This is more question than an issue. I want to use ebuildtester to verify my own ebuild for the guru repository.
https://gitweb.gentoo.org/repo/proj/guru.git/tree/app-misc/treesheets
It runs into a well known error with circular dependencies of harfbuzz and freetype.
https://wiki.gentoo.org/wiki/Portage/Help/Circular_dependencies#harfbuzz_and_freetype.

The relevant messsages from the ebuildtester run:
2025-10-15 14:19:40,259 - d3fb7b (stderr): * Error: circular dependencies: 2025-10-15 14:19:40,259 - d3fb7b (stdout): [nomerge ] x11-libs/wxGTK-3.2.8.1-r2:3.2-gtk3/3.2::gentoo USE="X lzma spell -curl -debug -doc -gstreamer -keyring -libnotify -opengl (-pch) -sdl -test -tiff -wayland -webkit" ABI_X86="(64) -32 (-x32)" 2025-10-15 14:19:40,259 - d3fb7b (stderr): 2025-10-15 14:19:40,259 - d3fb7b (stderr): (media-libs/freetype-2.13.3:2/2::gentoo, ebuild scheduled for merge) depends on 2025-10-15 14:19:40,259 - d3fb7b (stdout): [nomerge ] x11-libs/gtk+-3.24.51:3::gentoo USE="X introspection (-aqua) -broadway -cloudproviders -colord -cups -examples -gtk-doc -sysprof -test -vim-syntax -wayland -xinerama" ABI_X86="(64) -32 (-x32)" 2025-10-15 14:19:40,259 - d3fb7b (stderr): (media-libs/harfbuzz-11.4.5:0/6.0.0::gentoo, ebuild scheduled for merge) (buildtime) 2025-10-15 14:19:40,260 - d3fb7b (stderr): (media-libs/freetype-2.13.3:2/2::gentoo, ebuild scheduled for merge) (buildtime_slot_op) 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-themes/adwaita-icon-theme-48.1::gentoo USE="-branding" 4412 KiB 2025-10-15 14:19:40,260 - d3fb7b (stderr): 2025-10-15 14:19:40,260 - d3fb7b (stderr): * Note that circular dependencies can often be avoided by temporarily 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-themes/adwaita-icon-theme-legacy-46.2::gentoo 2009 KiB 2025-10-15 14:19:40,260 - d3fb7b (stderr): * disabling USE flags that trigger optional dependencies. 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-libs/wxGTK-3.2.8.1-r2:3.2-gtk3/3.2::gentoo USE="X lzma spell -curl -debug -doc -gstreamer -keyring -libnotify -opengl (-pch) -sdl -test -tiff -wayland -webkit" ABI_X86="(64) -32 (-x32)" 26807 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] app-text/gspell-1.14.0-r1:0/3::gentoo USE="introspection vala -gtk-doc -test" 114 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-libs/gtk+-3.24.51:3::gentoo USE="X introspection (-aqua) -broadway -cloudproviders -colord -cups -examples -gtk-doc -sysprof -test -vim-syntax -wayland -xinerama" ABI_X86="(64) -32 (-x32)" 13168 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] gnome-base/librsvg-2.60.0:2::gentoo USE="introspection vala -debug -gtk-doc -test" ABI_X86="(64) -32 (-x32)" 24320 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-libs/pango-1.57.0::gentoo USE="introspection -X -debug -examples -gtk-doc -sysprof -test" ABI_X86="(64) -32 (-x32)" 2507 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] media-libs/harfbuzz-11.4.5:0/6.0.0::gentoo USE="cairo glib graphite introspection truetype -debug -doc -experimental -icu -test" ABI_X86="(64) -32 (-x32)" 17726 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] media-libs/fontconfig-2.17.1:1.0::gentoo USE="nls -doc -test" ABI_X86="(64) -32 (-x32)" 1296 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] media-libs/freetype-2.13.3:2::gentoo USE="adobe-cff bzip2 cleartype-hinting harfbuzz png -X -brotli -debug -doc -fontforge -static-libs -svg -utils" ABI_X86="(64) -32 (-x32)" 0 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): [ebuild N ] x11-libs/cairo-1.18.4-r1::gentoo USE="X glib (-aqua) (-debug) -gtk-doc -lzo -test" ABI_X86="(64) -32 (-x32)" 41892 KiB 2025-10-15 14:19:40,260 - d3fb7b (stdout): 2025-10-15 14:19:40,260 - d3fb7b (stdout): Total: 12 packages (12 new), Size of downloads: 162609 KiB

How may I prepare ebuildtester or the stage container to go ahead with the emerge?

Begin with the linked app-misc/treesheets ebuild and reproduce the shown ebuildtester emerge output in the stage container. Investigate how ebuildtester or the stage container should be prepared to avoid the harfbuzz/freetype circular dependency; the issue is resolved when the requested emerge proceeds successfully.