emulators/wine-devel: Update to Wine 6.20

This includes the following changes:

• MSXml, XAudio, DInput and a few other modules converted to PE.
• A few system libraries are bundled with the source to support PE builds.
• HID joystick is now the only supported joystick backend in DirectInput.
• Better support for MSVCRT builds in Winelib.
• Various bug fixes.

Also, using our patches within this Port (for now):

• procfs no longer needs to be mounted on /proc, we use sysctl() instead.
• The Staging patchset will apply even if $PORTSDIR is a Git repository.

The latter requires lang/gawk as an additional EXTRACT_DEPENDS.

(The now bundled system libraries will trigger some follow-up changes,
but for now we're okay.)

Approved by: maintainer (= author)