patch 8.2.1133: Vim9: return type of add() is not specific enough

Problem:    Vim9: return type of add() is not specific enough.
Solution:   Return the type of the first argument. (closes #6395)
diff --git a/src/version.c b/src/version.c
index ed3f34a..6a22951 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1133,
+/**/
     1132,
 /**/
     1131,