patch 9.0.0400: GUI test sometimes hangs on CI

Problem:    GUI test sometimes hangs on CI.
Solution:   Delete a test file explicitly. (Ken Takata, closes #11072)
diff --git a/src/version.c b/src/version.c
index 025b576..a46236a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    400,
+/**/
     399,
 /**/
     398,