Auto merge of #29866 - mrobinson:run-unit-tests-on-main-workflow, r=atbrakhi

Run unit tests on the main Linux workflow

Not running unit tests on the main Linux workflow makes it faster, but also allows merging changes that break the unit tests. This change fixes that.

---
<!-- 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 do not require tests because they are CI changes.

<!-- 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. -->

.github/workflows/main.yml

@@ -52,6 +52,7 @@ jobs:
     with:
       layout: '2013'
       wpt: 'test'
+      unit-tests: true
 
   build-linux-layout-2020:
     name: Linux (layout-2020)
@@ -60,6 +61,7 @@ jobs:
     with:
       layout: '2020'
       wpt: 'test'
+      unit-tests: true
 
   build_result:
     name: homu build finished