Revert of Bring back compiling third_party/libpng in public.bzl (patchset #3 id:40001 of https://codereview.chromium.org/2044703006/ )

Reason for revert:
Breaking Google3

Original issue's description:
> Bring back compiling third_party/libpng in public.bzl
>
> Disable the optimizations for simplicity, as suggested in [1].
>
> Remove PNG_SKIP_SETJMP_CHECK, which is not defined in version 1.6.22.
>
> [1] https://codereview.chromium.org/2033063003/diff/20001/public.bzl#newcode84
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2044703006
>
> Committed: https://skia.googlesource.com/skia/+/e6939c15dc0c09f1348988dc56e50b6bea27b7ce

TBR=benjaminwagner@google.com,msarett@google.com,mtklein@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2090643002
1 file changed