patch 9.0.1321: vimscript test fails where using {expr} syntax

Problem:    vimscript test fails where using {expr} syntax.
Solution:   Only return FCERR_FAILED in call_user_func() for Vim9 script.
diff --git a/src/version.c b/src/version.c
index 20df490..41822fd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1321,
+/**/
     1320,
 /**/
     1319,