vimPlugins.skim: move to non-generated

Looks like it was missed in `overrides.nix` when it should be in
non-generated.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

pkgs/applications/editors/vim/plugins/non-generated/skim/default.nix

@@ -0,0 +1,9 @@
+{
+  vimUtils,
+  skim,
+}:
+vimUtils.buildVimPlugin {
+  pname = "skim";
+  inherit (skim) version;
+  src = skim.vim;
+}

pkgs/applications/editors/vim/plugins/overrides.nix

@@ -42,7 +42,6 @@
   parinfer-rust,
   ranger,
   ripgrep,
-  skim,
   sqlite,
   sshfs,
   statix,
@@ -3145,12 +3144,6 @@ in
     ];
   };
 
-  skim = buildVimPlugin {
-    pname = "skim";
-    inherit (skim) version;
-    src = skim.vim;
-  };
-
   skim-vim = super.skim-vim.overrideAttrs {
     dependencies = [ self.skim ];
   };