False positive in UnnecessaryLet

[BraisGabin]

Expected Behavior

UnnecessaryLet takes in account if the we use the return value of let or not.

Observed Behavior

UnnecessaryLet flags some of those.

Steps to Reproduce

val a = listOf<List<String>?>(listOf(""))
    .map { list -> list?.let { it + it } }

Context

This is the same problem that #2938 but with UnnecessaryLet instead of UnnecessaryApply

Your Environment

• Version of detekt used: 1.11.1