unused_crate_dependencies false positives for dev-dependencies added for Doctests

[laralove143]

I tried this code:

[dev-dependencies]
once_cell = "1.14"

/// ```rust
/// use once_cell::sync::Lazy;
/// ```
fn foo() {}

I expected to see this happen: No warning since once_cell is used in the Doctest

Instead, this happened: The warning is still emitted

Meta

rustc --version --verbose:

rustc 1.62.1 (e092d0b6b 2022-07-16)
binary: rustc
commit-hash: e092d0b6b43f2de967af0887873151bb1c0b18d3
commit-date: 2022-07-16
host: aarch64-apple-darwin
release: 1.62.1
LLVM version: 14.0.5