infra: Remove unused debug/cpu properties from tests. These are now configured through mb_config.pyl. We still pass in the properties to the lucicfg helper function set up the waterfall UI. Bug: angleproject:5114 Change-Id: Ib46ab95f5803a166fd2342679afbfcaa6f467c45 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2822233 Reviewed-by: Yuly Novikov <ynovikov@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>