patch 8.1.1842: test listed as flaky should no longer be flaky

Problem:    Test listed as flaky should no longer be flaky.
Solution:   Remove Test_popup_and_window_resize from the list of flaky tests.
            (Daniel Hahler, close #4807)

src/testdir/runtest.vim

@@ -329,7 +329,6 @@ let s:flaky_tests = [
       \ 'Test_paused()',
       \ 'Test_pipe_through_sort_all()',
       \ 'Test_pipe_through_sort_some()',
-      \ 'Test_popup_and_window_resize()',
       \ 'Test_quoteplus()',
       \ 'Test_quotestar()',
       \ 'Test_raw_one_time_callback()',

src/version.c

@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1842,
 /**/
     1841,
 /**/