Revert "Support for PAlloc's ScopedSafetyChecksExclusion"

This reverts commit d967fa42c04228424e1c22e1385c26dabcd56f8b.

Reason for revert: blocking G3 roll

Failure Link: <LINK TO FAILURE>

Original change's description:
> Support for PAlloc's ScopedSafetyChecksExclusion
>
> Provide SK_SCOPED_DISABLE_PARTITION_ALLOC_SAFETY_CHECKS
> macro in src/core/SkSafetyChecks.h, which defaults to empty
> unless defined by partition alloc settings.
>
> Bug: 534908403
> Change-Id: I4989cb3f75c8a6fb0662fcb9e9e58020adc10d93
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1293937
> Commit-Queue: Kaylee Lubick <kjlubick@google.com>
> Auto-Submit: Gregg Tavares <gman@google.com>
> Reviewed-by: Kaylee Lubick <kjlubick@google.com>

Bug: 534908403
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: Ie9ee4a460b161fe84729a0959f1d3997ffb7a8c3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1327676
Reviewed-by: Robert Phillips <robertphillips@google.com>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>