fix(lsp): avoid switching buffers on lsp attach (neovim#22689)

runtime/lua/vim/lsp.lua

@@ -1101,21 +1101,21 @@ function lsp.start_client(config)
  return true
  end
 
- local old_bufnr = vim.fn.bufnr('')
  local last_set_from = vim.fn.gettext('\n\tLast set from ')
  local line = vim.fn.gettext(' line ')
+ local scriptname
 
- vim.cmd.buffer(bufnr)
- local scriptname = vim.fn
- .execute('verbose set ' .. option .. '?')
- :match(last_set_from .. '(.*)' .. line .. '%d+')
- vim.cmd.buffer(old_bufnr)
+ vim.api.nvim_buf_call(bufnr, function()
+   scriptname = vim.fn
+  .execute('verbose set ' .. option .. '?')
+  :match(last_set_from .. '(.*)' .. line .. '%d+')
+ end)
 
  if not scriptname then
  return false
  end
- local vimruntime = vim.fn.getenv('VIMRUNTIME')
- return vim.startswith(vim.fn.expand(scriptname), vim.fn.expand(vimruntime))
+
+ return vim.startswith(vim.fn.expand(scriptname), vim.fn.expand('$VIMRUNTIME'))
  end
 
  ---@private