patch 8.1.0298: window resize test sometimes fails on Mac

Problem:    Window resize test sometimes fails on Mac.
Solution:   Add Test_popup_and_window_resize() to flaky tests.

src/testdir/runtest.vim

@@ -272,6 +272,7 @@ let s:flaky = [
       \ 'Test_paused()',
       \ 'Test_pipe_through_sort_all()',
       \ 'Test_pipe_through_sort_some()',
+      \ 'Test_popup_and_window_resize()',  " sometimes fails on Mac
       \ 'Test_quoteplus()',
       \ 'Test_quotestar()',
       \ 'Test_reltime()',

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    298,
 /**/
     297,
 /**/