fix(treesitter): fix ]c textobject mappings when in diff mode (#6911)

## Description
It seems that after
5985ca0cf1
the default `]c` Neovim mapping in diff mode broke. This is an attempt
to fix that.
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## Related Issue(s)
None, rather discussion #6910.
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  If this PR fixes any issues, please link to the issue here.
  - Fixes #<issue_number>
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## Screenshots

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## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/plugins/treesitter.lua

@@ -180,8 +180,10 @@ return {
             local desc = table.concat(parts, " or ")
             desc = (key:sub(1, 1) == "[" and "Prev " or "Next ") .. desc
             desc = desc .. (key:sub(2, 2) == key:sub(2, 2):upper() and " End" or " Start")
-            if not (vim.wo.diff and key:find("[cC]")) then
             vim.keymap.set({ "n", "x", "o" }, key, function()
+              if vim.wo.diff and key:find("[cC]") then
+                return vim.cmd("normal! " .. key)
+              end
               require("nvim-treesitter-textobjects.move")[method](query, "textobjects")
             end, {
               buffer = buf,
@@ -191,7 +193,6 @@ return {
           end
         end
       end
-      end
 
       vim.api.nvim_create_autocmd("FileType", {
         group = vim.api.nvim_create_augroup("lazyvim_treesitter_textobjects", { clear = true }),