Auto merge of #80395 - ehuss:lint-docs-warn-missing, r=Mark-Simulacrum
Auto merge of #80395 - ehuss:lint-docs-warn-missing, r=Mark-Simulacrum

lint-docs: Warn on missing lint when documenting.

In #79522, I missed converting one of the errors to a warning, in the situation where a lint is missing.  This was unearthed by the renaming of overlapping-patterns (#78242).  This will still be validated during the test phase.

aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust