internal/syscall/windows/registry: remove TestWalkFullRegistry due to false assumptions

This test's existence was predicated upon assumptions about the full
range of known data types and known data into those types. However,
we've learned from Microsoft that there are several undocumented secret
registry types that are in use by various parts of Windows, and we've
learned from inspection that many Microsoft uses of registry types don't
strictly adhere to the recommended value size. It's therefore foolhardy
to make any assumptions about what goes in and out of the registry, and
so this test, as well as its "blacklist", are meaningless.

Fixes #35084

Change-Id: I6c3fe5fb0e740e88858321b3b042c0ff1a23284e
Reviewed-on: https://go-review.googlesource.com/c/go/+/203604


Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>