Attached a patch that I tested earier. Works on some cases, but breaks build on some environments, so not considered at the moment. Submitted just for the benefit of downstreams that want to apply it locally (for whose it does not break anything)
Reply To cazfi
Works on some cases, but breaks build on some environments
New version, considered a commit candidate, makes MagickWand support optional. So it's available on some cases, but can be disabled when it won't work. Disabling it would be the safe default, but this patch enables it by default - like autotools side does despite similar build problems there. Installer_cross/Meson scripts disable it.
New version that disables the support also from Msys2 Makefile.meson. The reason for that is not that it would not build, but that it requires packaging changes after it has built linking against new libraries. New ticket created about those changes -> #45141
Meson based build does not detect MagickWand, and never enables related features. It should.