Auto merge of #26628 - gterzian:shutdown_workers, r=asajeffrey

Improve worker shutdown

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FIX #26548
FIX #25212

and also  a step towards https://github.com/servo/servo/issues/26502

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- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because ___

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components/script/dom/bindings/trace.rs

@@ -135,6 +135,7 @@ use std::path::PathBuf;
 use std::rc::Rc;
 use std::sync::atomic::{AtomicBool, AtomicUsize};
 use std::sync::{Arc, Mutex};
+use std::thread::JoinHandle;
 use std::time::{Instant, SystemTime};
 use style::animation::ElementAnimationSet;
 use style::attr::{AttrIdentifier, AttrValue, LengthOrPercentageOrAuto};
@@ -168,6 +169,7 @@ use webxr_api::SwapChainId as WebXRSwapChainId;
 use webxr_api::{Finger, Hand, Ray, View};
 
 unsafe_no_jsmanaged_fields!(Tm);
+unsafe_no_jsmanaged_fields!(JoinHandle<()>);
 
 /// A trait to allow tracing (only) DOM objects.
 pub unsafe trait JSTraceable {