fix: remove unused variable warning on Windows builds

[joshrotenberg]

Issue

Fixes #382

Windows build was showing an unused variable warning because the metadata variable was only used inside a #[cfg(unix)] block.

Fix

Moved the #[cfg(unix)] attribute to apply to the entire if statement, preventing the variable binding from being created on Windows.

Before

if let Ok(metadata) = fs::metadata(parent_dir) {
    #[cfg(unix)]
    {
        // use metadata
    }
}

After

#[cfg(unix)]
if let Ok(metadata) = fs::metadata(parent_dir) {
    // use metadata
}

Testing

This is a test PR for our automated release workflow. Once merged:

1. release-plz should create a version bump PR
2. Merging that PR should publish to crates.io and create a tag
3. Tag should trigger cargo-dist and Docker builds

Let's verify the end-to-end automation works!