patch 8.2.2204: Vim9: using -> both for method and lambda is confusing

Problem:    Vim9: using -> both for method and lambda is confusing.
Solution:   Use => for lambda in :def function.
diff --git a/src/version.c b/src/version.c
index e1e7856..df91534 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2204,
+/**/
     2203,
 /**/
     2202,