Auto merge of #124539 - Urgau:non-local-defs_modulo_modules, r=lcnr

Consider inner modules to be local in the `non_local_definitions` lint

This PR implements the [proposed fix](rust-lang/rust#124396 (comment)) for #124396, that is to consider inner modules to be local in the `non_local_definitions` lint.

This PR is voluntarily kept as minimal as possible so it can be backported easily.

T-lang [nomination](rust-lang/rust#124396 (comment)) will need to be removed before this can be merged.

Fixes *(nearly, needs backport)* rust-lang/rust#124396