vim-patch:8.2.0162: balloon test fails in the GUI

Problem:    Balloon test fails in the GUI.
Solution:   Skip test in the GUI.

7d8ea0b241

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/testdir/test_functions.vim

@@ -1320,6 +1320,9 @@ func Test_balloon_show()
 
   " This won't do anything but must not crash either.
   call balloon_show('hi!')
+  if !has('gui_running')
+    call balloon_show(range(3))
+  endif
 endfunc
 
 func Test_shellescape()