Auto merge of #29748 - Loirooriol:sync, r=mrobinson

Backport several style changes from Gecko

<!-- Please describe your changes on the following line: -->

---
<!-- 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
- [ ] These changes fix #___ (GitHub issue number if applicable)

<!-- Either: -->
- [X] There are tests for these changes OR
- [ ] These changes do not require tests because ___

<!-- 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. -->

servo-tidy.toml

@@ -91,6 +91,11 @@ packages = [
 # Files that are ignored for all tidy and lint checks.
 files = [
   "./components/net/tests/parsable_mime/text",
+  # These are ignored to avoid diverging from Gecko
+  "./components/style/properties/helpers.mako.rs",
+  "./components/style/stylesheets/rule_parser.rs",
+  "./components/style/stylist.rs",
+  "./components/style/values/computed/image.rs",
   # Mako does not lend itself easily to splitting long lines
   "./components/style/properties/helpers/animated_properties.mako.rs",
   "./components/style/properties/shorthands/text.mako.rs",