patch 8.2.4870: Vim9: expression in :substitute is not compiled

Problem:    Vim9: expression in :substitute is not compiled.
Solution:   Use an INSTR instruction if possible. (closes #10334)
diff --git a/src/version.c b/src/version.c
index 1237ebf..3f7825e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4870,
+/**/
     4869,
 /**/
     4868,