Auto merge of #29423 - sagudev:ci2, r=jdm

General quick check for PRs and forks.

Pull request workflow was changed to more general Quick check workflow that is meant to be run on PR and all branches not covered by main workflow.

BONUS: I used [xvfb-run](https://manpages.ubuntu.com/manpages/xenial/man1/xvfb-run.1.html) to enable smoketest on Linux.

---
<!-- 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 are partial fix for #29379

<!-- Either: -->
- [ ] There are tests for these changes OR
- [X] These changes do not require tests because there are only 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/nightly-rust.yml

@@ -29,5 +29,7 @@ jobs:
           python3 ./mach bootstrap
       - name: Release build
         run: python3 ./mach build --release
+      - name: Smoketest
+        run: xvfb-run python3 ./mach smoketest
       - name: Unit tests
         run: python3 ./mach test-unit --release

.github/workflows/quick-check.yml

@@ -1,7 +1,9 @@
-name: Pull request
+name: Quick check
 on:
   pull_request:
-    branches: ["**"]
+  push:
+    branches:
+      [ "**", "!auto", "!try", "!try-linux", "!try-mac", "!try-windows", "!try-wpt"]
 
 env:
   RUST_BACKTRACE: 1
@@ -9,6 +11,7 @@ env:
 
 jobs:
   build-linux:
+    if: github.repository == 'servo/servo' || github.event_name == 'push'
     name: Build (Linux)
     runs-on: ubuntu-20.04
     steps:
@@ -23,6 +26,8 @@ jobs:
         run: python3 ./mach test-tidy --no-progress --all
       - name: Release build
         run: python3 ./mach build --release
+      - name: Smoketest
+        run: xvfb-run python3 ./mach smoketest
       - name: Unit tests
         run: python3 ./mach test-unit --release
       - name: Lockfile check