patch 8.2.1584: Vim9: cannot use "true" for "skipstart" in prop_find()

Problem:    Vim9: cannot use "true" for "skipstart" in prop_find().
Solution:   Use dict_get_bool() instead of tv_get_number(). (closes #6852)
diff --git a/src/version.c b/src/version.c
index de956a6..116fab9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1584,
+/**/
     1583,
 /**/
     1582,