patch 8.2.3970: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/vim9execute.c b/src/vim9execute.c
index ea4c85e..a0b1fe4 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -3148,7 +3148,7 @@
 			if (item != NULL)
 			{
 			    SOURCING_LNUM = iptr->isn_lnum;
-			    semsg(_(e_duplicate_key), key);
+			    semsg(_(e_duplicate_key_in_dicitonary), key);
 			    dict_unref(dict);
 			    goto on_error;
 			}