Build tools on NoGPU bots.

Build tools on NoGPU bots.

I was just lazy disabling this before.  It turns out to not be difficult.

This gets us slightly better testing out of the NoGPU bot, as we now know
not only that Skia compiles, but also that DM and nanobench can link (and
thus that Skia's got enough compiled in it to be a coherent library).

skpbench requires GPU support.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2356283002

Review-Url: https://codereview.chromium.org/2356283002