Don't user display empty string for absolute path CWD

[konstin]

With the previous order an absolute path would become an empty string.

[konstin]

There's actually some existing non-tracing outputs affected by this, I've updated this snapshots.

[zanieb]

I think we shouldn't change this, maybe we need to detect this case now? :(

[zanieb]

I think it's just changing

#[error("{} has malformed dependency groups", if path.is_empty() && package.is_empty() {
    "Project".to_string()
} else if path.is_empty() {
    format!("Project `{package}`")
} else if package.is_empty() {
    format!("`{path}`")
} else {
    format!("Project `{package} @ {path}`")
})]

to handle "." instead of ""