gnome.gedit: fix typelib path

We patch gobject-introspection and meson to store absolute paths to libraries in typelibs but that requires the install_dir is an absolute path.

pkgs/desktops/gnome/apps/gedit/correct-gir-lib-path.patch

@@ -0,0 +1,13 @@
+diff --git a/gedit/meson.build b/gedit/meson.build
+index a8683e61a..fc48669f7 100644
+--- a/gedit/meson.build
++++ b/gedit/meson.build
+@@ -191,7 +191,7 @@ libgedit_shared_lib = shared_library(
+   c_args: libgedit_c_args,
+   link_args: libgedit_link_args,
+   install: true,
+-  install_dir: get_option('libdir') / 'gedit',
++  install_dir: get_option('prefix') / get_option('libdir') / 'gedit',
+ )
+ 
+ # GObject Introspection

pkgs/desktops/gnome/apps/gedit/default.nix

@@ -30,6 +30,12 @@ stdenv.mkDerivation rec {
     sha256 = "149ngl9qw6h59546lir1pa7hvw23ppsnqlj9mfqphmmn5jl99qsm";
   };
 
+  patches = [
+    # We patch gobject-introspection and meson to store absolute paths to libraries in typelibs
+    # but that requires the install_dir is an absolute path.
+    ./correct-gir-lib-path.patch
+  ];
+
   nativeBuildInputs = [
     desktop-file-utils
     itstool