Always build our own zlib.

Always build our own zlib.

If we want to have an MSAN build, it'll help if we can build our own zlib
so that it's instrumented by MSAN.

Today we build our own zlib on Windows, but require the system to provide it
elsewhere.  This just makes everyone build it (except Android framework of course).

This drops the SIMD files.  They're only used to accelerate deflate
(compression), so they're not terribly interesting to us.  Again, this only
really changes compression speed on Windows bots... pretty niche.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1665843002

Review URL: https://codereview.chromium.org/1665843002