patch 8.2.1337: Vim9: cannot use empty key in dict assignment

Problem:    Vim9: cannot use empty key in dict assignment.
Solution:   Allow empty key. (closes #6591)
diff --git a/src/version.c b/src/version.c
index bf22a76..661875a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1337,
+/**/
     1336,
 /**/
     1335,