Rollup merge of rust-lang#77555 - camelid:patch-8, r=Mark-Simulacrum

Allow anyone to set regression labels

Cc https://rust-lang.zulipchat.com/#narrow/stream/241545-t-release/topic/improve.20reporting.20of.20regressions/near/212245535

r? @Mark-Simulacrum

Author: JohnTitor

triagebot.toml

@@ -3,6 +3,7 @@ allow-unauthenticated = [
     "C-*", "A-*", "E-*", "NLL-*", "O-*", "S-*", "T-*", "WG-*", "F-*",
     "D-*",
     "requires-nightly",
+    "regression-*",
     # I-* without I-nominated
     "I-*", "!I-nominated",
     "AsyncAwait-OnDeck",