Duplicate warnings after rustup fix

[phansch]

The ui/deprecated.stderr and ui/rename.stderr contain duplicate lint emissions in two cases after rustup to rust-lang/rust#57726.

I think the reason for the duplicates is this change here:
https://github.com/rust-lang/rust/blob/9b5535a6f38340d3be8fcae1822a04ba3febf82f/src/librustc/lint/context.rs#L1325
They now run early_lint_crate twice. Once with the builtin lints and once with the registered lint passes. Those warnings aren't generated by a normal lint but rather when the lints are looked up from attributes which happens twice now.
I'm not sure why only the first is duplicated though. Maybe because they filter duplicates but the first one has a note. 🤔

Originally posted by @mikerite in #3705 (comment)

[flip1995]

Maybe because they filter duplicates but the first one has a note.

I ran into that myself before. Can confirm that this is an issue: rust-lang/rust#53762 (comment)

The weird thing is, that it only happens on some lints and not on all lints.

[camsteffen]

This is fixed.