Add clubby789 to users_on_vacation

Author: clubby789

triagebot.toml

@@ -490,7 +490,7 @@ cc = ["@nnethercote"]
 [assign]
 warn_non_default_branch = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
-users_on_vacation = ["jyn514", "WaffleLapkin"]
+users_on_vacation = ["jyn514", "WaffleLapkin", "clubby789"]
 
 [assign.adhoc_groups]
 compiler-team = [