Exclude "girepository" as it doesn't build on Windows.

Patch originally from Thomas Nielsen for MCM.

--- meson.build
+++ meson.build
@@ -98,7 +98,6 @@
 gobjectinc = include_directories('gobject')
 gmoduleinc = include_directories('gmodule')
 gioinc = include_directories('gio')
-girepoinc = include_directories('girepository')
 
 glib_prefix = get_option('prefix')
 glib_bindir = join_paths(glib_prefix, get_option('bindir'))
@@ -2571,7 +2570,6 @@
 subdir('gthread')
 subdir('gmodule')
 subdir('gio')
-subdir('girepository')
 subdir('fuzzing')
 subdir('tests')
 
