Rollup merge of #141661 - Urgau:deny-dangerous_implicit_autorefs, r=traviscross

Make the `dangerous_implicit_autorefs` lint deny-by-default

I intended for the `dangerous_implicit_autorefs` lint to be deny-by-default, the [T-lang nomination comment](rust-lang/rust#123239 (comment)) even clearly mentioned deny-by-default, but somehow I and other missed that it is only warn-by-default.

I think the lint should still be deny-by-default as the implicit aliasing requirements can be quite dangerous.

In any-case, opening this PR for T-lang awareness.

`@rustbot` label +I-lang-nominated +T-lang
r? `@traviscross`

Author: GuillaumeGomez