[cq] Always run IWYU on tests

https://skia-review.googlesource.com/c/skia/+/630016 was an
example of a CL that did not affect //tests/... but did
require changes there. The builds seem fast enough to always
run them on the CQ.

Change-Id: I06f85bf81880544c4b405a518160f83070800eca
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/630541
Reviewed-by: Ravi Mistry <rmistry@google.com>
2 files changed