fix(lsp): set concealcursor='' in LSP floating windows #36596

Problem:
Users often jump and navigate through LSP windows to yank text.
Concealed markdown can make navigation through hyperlinks and code
blocks more difficult.

Solution:
Change 'concealcursor' from 'n' to '' to preserve clean display
while improving navigation and selection of the LSP response.

Closes #36537

runtime/lua/vim/lsp/util.lua

@@ -1769,7 +1769,7 @@ function M.open_floating_preview(contents, syntax, opts)
 
   if do_stylize then
     vim.wo[floating_winnr].conceallevel = 2
-    vim.wo[floating_winnr].concealcursor = 'n'
+    vim.wo[floating_winnr].concealcursor = ''
     vim.bo[floating_bufnr].filetype = 'markdown'
     vim.treesitter.start(floating_bufnr)
     if not opts.height then