Function diff_dependency_graph 

pub fn diff_dependency_graph(
    old_sbom: &NormalizedSbom,
    new_sbom: &NormalizedSbom,
    component_matches: &HashMap<CanonicalId, Option<CanonicalId>>,
    config: &GraphDiffConfig,
) -> (Vec<DependencyGraphChange>, GraphChangeSummary)

Perform graph-aware diff between two SBOMs