all: update vendored golang.org/x/sys

all: update vendored golang.org/x/sys

Update the vendored x/sys to pick up CL 368994, which remove the
declaration of function darwinSupportsAVX512 in cpu/cpu_gc_x86.go.

The following commands were used:

  go get -d golang.org/x/sys@97ca703d548df069cb02aacea9efc3093ffdc3c4
  go mod tidy
  go mod vendor

Fixes #49942

Change-Id: I05162a051f572bf8599be198a6033384b7d19445
Reviewed-on: https://go-review.googlesource.com/c/go/+/369454
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>