Auto merge of #27163 - alarsyo:23053-layout-queries-disconnected-frames-panic, r=jdm

Return Option for Window's layout channel

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`Window::layout_chan()` now returns an `Option<Sender<Msg>>`, returning `None` if the window is dead.

FIX #26969
FIX #26429
FIX #21208
FIX #19092
FIX #22559
FIX #22584
FIX #22652

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #23053

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- [x] There are tests for these changes

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This is my first contribution, I'm trying to figure things out!

This fix passes the test case shown in #23053, however I don't know what the behavior should be in `Document` and `ScriptThread` if `Window::is_alive()` is false : simply ignore it, don't do anything ? Or is this something that should not happen now that we return false in `Window::force_reflow()` ?

I'm not sure about the directory where the test case should go, any advice?

tests/wpt/mozilla/meta/MANIFEST.json

@@ -13361,6 +13361,13 @@
       {}
      ]
     ],
+    "detached_layout.html": [
+     "b9fe090cc29c147f493732327e36b06702c4f846",
+     [
+      null,
+      {}
+     ]
+    ],
     "deterministic-raf.html": [
      "441664829a14379ebc92306f42ab0bad6581257e",
      [