[release-branch.go1.17] misc/cgo/testplugin: skip TestIssue25756pie on darwin/arm64 builder

Repeat of CL 321349 for macOS 12. We won't need to do this again -- the
test is passing at tip.

Updates #46239.

Change-Id: Ib279ada443ee03eb8e70fde4bbfba65ce0f6322e
Reviewed-on: https://go-review.googlesource.com/c/go/+/369748


Trust: Heschi Kreinick <heschi@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>