Rollup merge of #117562 - pitaj:triagebot_no-merges, r=Mark-Simulacrum

triagebot no-merges: exclude different case

"Subtree update" as well

To address [this on zulip](https://rust-lang.zulipchat.com/#narrow/stream/242791-t-infra/topic/can't.20suppress.20merge.20commit.20warning)

cc `@bjorn3`

r? `@mark-simulacrum`

triagebot.toml

@@ -415,7 +415,7 @@ Issue #{number} "{title}" has been added.
 """
 
 [no-merges]
-exclude_titles = ["Rollup of", "subtree update"]
+exclude_titles = ["Rollup of", "subtree update", "Subtree update"]
 labels = ["has-merge-commits", "S-waiting-on-author"]
 
 [github-releases]