www/epiphany: drop unused Meson options after 6106add6f4e9

meson.build:1:0: ERROR: Unknown options: "distributor_name"

https://gitlab.gnome.org/GNOME/epiphany/-/commit/554a375e8a90

PR: 259080
Reported by: antoine (via exp-run)
Regressed by: https://github.com/mesonbuild/meson/commit/dbf2ace6ca1c