patch 8.2.1937: Vim9: test for confirm modifier fails in some situations

Problem:    Vim9: test for confirm modifier fails in some situations.
Solution:   Add a short wait.  Handle failure better.
diff --git a/src/version.c b/src/version.c
index 82bb09d..65050b9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1937,
+/**/
     1936,
 /**/
     1935,