Use --ignore-default-expectations for WebGPU WPT tests; fix CQ triggers

This allows us to write expectations for tests, instead of having to
modify the tests themselves (e.g. by removing a line from cts.html).
I forgot I could do this in the original patch.

Also fixes commit-queue.cfg to trigger Dawn CQ bots on appropriate files.

Bug: 984818
Change-Id: I16e708c35209137266982da1107c1f34ff72026e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1759393
Reviewed-by: Kenneth Russell <[email protected]>
Commit-Queue: Kai Ninomiya <[email protected]>
Cr-Commit-Position: refs/heads/master@{#688342}
diff --git a/third_party/blink/web_tests/WebGPUExpectations b/third_party/blink/web_tests/WebGPUExpectations
new file mode 100644
index 0000000..71d0a02
--- /dev/null
+++ b/third_party/blink/web_tests/WebGPUExpectations
@@ -0,0 +1,2 @@
+# WebGPU tests are only run on GPU bots, so they are skipped by default and run
+# separately from other Web Tests, with this expectations file.