fix(deep-link): import ComponentHandle for Weak::as_weak

Static-review miss (qbz crate can't be check-built without the 30 GB
qbz-ui unit): as_weak() is a ComponentHandle trait method, so the trait
must be in scope. Found by the owner smoke build (E0599, qbz/src/
deep_link.rs:153) — the sole error in the crate.

km

crates/qbz/src/deep_link.rs

@@ -27,6 +27,7 @@
 use std::sync::{Arc, Mutex};
 
 use qbz_app::shell::AppRuntime;
+use slint::ComponentHandle;
 
 use crate::adapter::SlintAdapter;
 use crate::artwork;