meson: Use dependency() for gpme Since version 0.51, we can rely on Meson to do the correct thing when calling `dependency('gpgme')`. This makes both the meson.build and the GPG version checking script quite a bit cleaner. It also remove the need for gpgme-config which isn't shipped currently in Debian by libgpgme-dev, by using pkgconfig. This patch is mostly an adaptation of https://gitlab.gnome.org/GNOME/seahorse/-/commit/f862919765f92640016604e65eb6c535fa9a80a2.
