plugins/gitsigns: remove deprecated option 'show_deleted'

lewis6991/gitsigns.nvim#1174

Author: GaetanLepage

plugins/by-name/gitsigns/settings-options.nix

@@ -141,12 +141,6 @@ in
     corresponding highlight group in `signs.*.hl`.
   '';
 
-  show_deleted = defaultNullOpts.mkBool false ''
-    Show the old version of hunks inline in the buffer (via virtual lines).
-
-    Note: Virtual lines currently use the highlight `GitSignsDeleteVirtLn`.
-  '';
-
   diff_opts =
     let
       diffOptType = types.submodule {

tests/test-sources/plugins/by-name/gitsigns/default.nix

@@ -40,7 +40,6 @@
         signcolumn = true;
         numhl = false;
         linehl = false;
-        show_deleted = false;
         diff_opts = {
           algorithm = "myers";
           internal = false;