runtime: skip TestVectoredHandlerExceptionInNonGoThread

runtime: skip TestVectoredHandlerExceptionInNonGoThread

windows-amd-2012 builder seems to have some problems handling
exception thrown in external C code which is affecting
TestVectoredHandlerExceptionInNonGoThread.
The issue is known and discussed in #49681.

This Cl skips the offending test on windows-amd-2012.

Change-Id: I7ca4353c9e531f0d75ac6a8dbd809acfa1f15bf9
Reviewed-on: https://go-review.googlesource.com/c/go/+/444616
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>