Similarly to CL 138676, skip TestUnixConnLocalWindows on windows/arm.

Fixes #28061

Change-Id: I2270d2f9d268e85ea567be0c0c37c48e4d482282
Reviewed-on: https://go-review.googlesource.com/c/140397
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>