Devtools: Switch to GenericChannel and GenericCallback (#41051)

Switch the devtools part to GenericCallback and GenericSender.
To keep the diff small the names where not changes as a Sender almost
fills the same requirement as a callback.

Testing: As this is mostly type changes, the compilation is the test but
also devtools seem to work fine with these changes. ./mach try run is
here: https://github.com/Narfinger/servo/actions/runs/19931697694

---------

Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>

components/script/serviceworker_manager.rs

@@ -465,7 +465,7 @@ fn update_serviceworker(
     Arc<AtomicBool>,
 ) {
     let (sender, receiver) = unbounded();
-    let (_devtools_sender, devtools_receiver) = ipc::channel().unwrap();
+    let (_devtools_sender, devtools_receiver) = generic_channel::channel().unwrap();
     let worker_id = ServiceWorkerId::new();
 
     let (control_sender, control_receiver) = unbounded();