patch 8.2.1250: Vim9: cannot use the g:, b:, t: and w: namespaces

Problem:    Vim9: cannot use the g:, b:, t: and w: namespaces.
Solution:   Add instructions to push a dict for the namespaces. (closes #6480)
diff --git a/src/version.c b/src/version.c
index 6ffb98d..936e4df 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1250,
+/**/
     1249,
 /**/
     1248,