dco-win: update GH Actions config file

dco-win: update GH Actions config file

In order to build OpenVPN with DCO support on Windows there is no need
to pull the full ovpn-dco-win source code, because we now ship the
UAPI header within OpenVPN directly. This also eliminates the need
to specify the DCO_SOURCEDIR var.

At the same time, DCO is always enabled therefore passing --enable-dco
at configure time is not needed anymore.

Signed-off-by: Lev Stipakov <lev@openvpn.net>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20220826084111.239523-1-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25120.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>