vim-patch:8.1.1860: map timeout test is flaky

Problem:    Map timeout test is flaky.
Solution:   Add test to list of flaky tests.  Increase timeout.
ea94c85516

src/nvim/testdir/runtest.vim

@@ -280,6 +280,7 @@ endif
 let s:flaky_tests = [
       \ 'Test_cursorhold_insert()',
       \ 'Test_exit_callback_interval()',
+      \ 'Test_map_timeout_with_timer_interrupt()',
       \ 'Test_oneshot()',
       \ 'Test_out_cb()',
       \ 'Test_paused()',

src/nvim/testdir/test_mapping.vim

@@ -288,7 +288,7 @@ func Test_map_timeout_with_timer_interrupt()
   let g:val = 0
   nnoremap \12 :let g:val = 1<CR>
   nnoremap \123 :let g:val = 2<CR>
-  set timeout timeoutlen=100
+  set timeout timeoutlen=200
 
   func ExitCb(job, status)
     let g:timer = timer_start(1, {_ -> feedkeys("3\<Esc>", 't')})