patch 8.2.2582: Vim9: screendump test fails on MS-Windows

Problem:    Vim9: screendump test fails on MS-Windows.
Solution:   Use :function instead of :def.
diff --git a/src/version.c b/src/version.c
index 5ae184e..447b6e6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2582,
+/**/
     2581,
 /**/
     2580,