doc: improve release note for Windows hosts file being respected

doc: improve release note for Windows hosts file being respected

Make a grammar fix (searches -> searches for) and simplify "when
building with" phrase.

For #61422.

Change-Id: I179b3816c0e223a16e4969290b2c1ed19d44c556
Reviewed-on: https://go-review.googlesource.com/c/go/+/549457
Reviewed-by: Bryan Mills <bcmills@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>