Auto merge of #23517 - oneturkmen:prep-for-composite-void, r=jdm

Make prepare_for_composite return void

<!-- Please describe your changes on the following line: -->
Changed the signature of `fn prepare_for_composite(...)` to return void (unit) instead of boolean.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #23492 (GitHub issue number if applicable)

<!-- Either: -->
- [ ] There are tests for these changes OR
- [x] These changes do not require tests because these are clean-up changes (do not include new feature or fixed bug).

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/23517)
<!-- Reviewable:end -->

ports/glutin/headed_window.rs

@@ -510,9 +510,8 @@ impl WindowMethods for Window {
         self.animation_state.set(state);
     }
 
-    fn prepare_for_composite(&self) -> bool {
+    fn prepare_for_composite(&self) {
         self.gl_context.borrow_mut().make_current();
-        true
     }
 }
 

ports/glutin/headless_window.rs

@@ -194,7 +194,5 @@ impl WindowMethods for Window {
         self.animation_state.set(state);
     }
 
-    fn prepare_for_composite(&self) -> bool {
-        true
-    }
+    fn prepare_for_composite(&self) { }
 }

ports/libsimpleservo/api/src/lib.rs

@@ -580,10 +580,9 @@ impl EmbedderMethods for ServoEmbedderCallbacks {
 }
 
 impl WindowMethods for ServoWindowCallbacks {
-    fn prepare_for_composite(&self) -> bool {
+    fn prepare_for_composite(&self) {
         debug!("WindowMethods::prepare_for_composite");
         self.host_callbacks.make_current();
-        true
     }
 
     fn present(&self) {