test: use cgo.Incomplete instead of go:notinheap for "run" tests

test: use cgo.Incomplete instead of go:notinheap for "run" tests

Same as CL 421880, but for test directory.

Updates #46731

Change-Id: If8d18df013a6833adcbd40acc1a721bbc23ca6b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/421881
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>