patch 8.2.2668: Vim9: omitting "call" for "confirm()" does not give an error

Problem:    Vim9: omitting "call" for "confirm()" does not give an error.
Solution:   Do not recognize a modifier followed by "(".
diff --git a/src/version.c b/src/version.c
index a5a0079..716f41e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2668,
+/**/
     2667,
 /**/
     2666,