crypto/x509: attempt to prime windows root pool before hybrid test

crypto/x509: attempt to prime windows root pool before hybrid test

In TestHybridPool attempt to prime to the windows root pool before
the real test actually happens. This is a bit of a band-aid, with
a better long term solution discussed in #52108.

Updates #51599

Change-Id: I406add8d9cd9e3fae37bfc20b97f5479c10a52c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/405914
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>