feat(lua): replace buffer with buf in vim.keymap.set/del #38360

The `buffer` option remains functional but is now undocumented.
Providing both will raise an error. Since providing `buf` was disallowed
before, there is no code that will break due to using `buffer` alongside
`buf`.

runtime/lua/vim/lsp/client.lua

@@ -1376,7 +1376,7 @@ local function reset_defaults(bufnr)
   vim._with({ buf = bufnr }, function()
     local keymap = vim.fn.maparg('K', 'n', false, true)
     if keymap and keymap.callback == lsp.buf.hover and keymap.buffer == 1 then
-      vim.keymap.del('n', 'K', { buffer = bufnr })
+      vim.keymap.del('n', 'K', { buf = bufnr })
     end
   end)
 end