Auto merge of #132854 - RalfJung:query-key-limit, r=compiler-errors

query/plumbing: adjust comment to reality

The limit for the query key size got changed recently in rust-lang/rust@f51ec11 but the comment was not updated.

Though maybe it is time to intern `CanonicalTypeOpAscribeUserTypeGoal` rather than copying it everywhere?

r? `@lcnr`

Author: bors