fix(test): typing

runtime/lua/vim/lsp/client.lua

@@ -225,7 +225,7 @@ local validate = vim.validate
 --- If {status} is `true`, the function returns {request_id} as the second
 --- result. You can use this with `client.cancel_request(request_id)` to cancel
 --- the request.
---- @field request fun(method: string, params: table?, handler: lsp.Handler?, bufnr: integer): boolean, integer?
+--- @field request fun(method: string, params: table?, handler: lsp.Handler?, bufnr: integer?): boolean, integer?
 ---
 --- Sends a request to the server and synchronously waits for the response.
 --- This is a wrapper around {client.request}
@@ -647,10 +647,10 @@ end
 --- checks for capabilities and handler availability.
 ---
 --- @param method string LSP method name.
---- @param params table|nil LSP request params.
---- @param handler lsp.Handler|nil Response |lsp-handler| for this method.
---- @param bufnr integer Buffer handle (0 for current).
---- @return boolean status, integer|nil request_id {status} is a bool indicating
+--- @param params? table LSP request params.
+--- @param handler? lsp.Handler Response |lsp-handler| for this method.
+--- @param bufnr? integer Buffer handle (0 for current).
+--- @return boolean status, integer? request_id {status} is a bool indicating
 --- whether the request was successful. If it is `false`, then it will
 --- always be `false` (the client has shutdown). If it was
 --- successful, then it will return {request_id} as the