servo: Merge #19609 - remove unsued IpcReceiver (from tigercosmos:q1); r=emilio

<!-- Please describe your changes on the following line: -->
```
warning: unused import: `IpcReceiver`
  --> components/canvas/canvas_paint_thread.rs:14:41
   |
14 | use ipc_channel::ipc::{self, IpcSender, IpcReceiver};
   |                                         ^^^^^^^^^^^
   |
   = note: #[warn(unused_imports)] on by default
```

recently I have done similar commits for three times
Shall we merge #19573?

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

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Source-Repo: https://github.com/servo/servo
Source-Revision: 8f786d4e964ee67f80462e8af9cef1e2bbd328a2

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 3e9d77cfb8b7acd85f0a3d3610ad7242162100c9

servo/components/canvas/canvas_paint_thread.rs

@@ -11,7 +11,7 @@ use azure::azure_hl::SurfacePattern;
 use canvas_traits::canvas::*;
 use cssparser::RGBA;
 use euclid::{Transform2D, Point2D, Vector2D, Rect, Size2D};
-use ipc_channel::ipc::{self, IpcSender, IpcReceiver};
+use ipc_channel::ipc::{self, IpcSender};
 use num_traits::ToPrimitive;
 use std::borrow::ToOwned;
 use std::mem;