patch 8.2.1460: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more messages into errors.h.
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 320340f..fee2971 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -1900,7 +1900,7 @@
     }
     if (in_vim9script())
     {
-	emsg(_("E1040: Cannot use :scriptversion after :vim9script"));
+	emsg(_(e_cannot_use_scriptversion_after_vim9script));
 	return;
     }