libpeas: correct gtk .pc file

Here's the diff post meson:
-prefix=/nix/store/hfrrby8wapcz17v927as18z3znqdv2ps-libpeas-1.22.0
-exec_prefix=${prefix}
-libdir=${exec_prefix}/lib
+prefix=/nix/store/sc8h3m6fv3zdjzpkimhm4yqarafhjp6y-libpeas-1.24.0
+libdir=${prefix}/lib
 includedir=${prefix}/include

-Name: libpeas-gtk
-Description: libpeas-gtk, a GObject plugins library (Gtk widgets)
-Requires: glib-2.0 >= 2.38.0, gtk+-3.0 >= 3.0.0, libpeas-1.0 >= 1.22.0
-Version: 1.22.0
+Name: libpeas-gtk-1.0
+Description: GObject plugins library widgetery
+Version: 1.24.0
+Requires.private: libpeas-1.0, glib-2.0 >=  2.38.0, gobject-2.0 >=  2.38.0, gobject-introspection-1.0 >=  1.39.0, gtk+-3.0 >=  3.0.0, gmodule-2.0 >=  2.38.0, gio-2.0 >=  2.38.0
+Libs: -L${prefix}//lib  -lpeas-gtk-1.0
 Cflags: -I${includedir}/libpeas-1.0
-Libs: -L${libdir} -lpeas-gtk-1.0

As we can see, all the requires got moved into private.
This appears to have broken midori [0]

[0]: https://hydra.nixos.org/build/101627205