builder/windows: drop package.accept_keywords

There's an existing
/etc/portage/package.accept_keywords/cross-x86_64-w64-mingw32 that accepts
testing versions of mingw64-runtime, binutils, and gcc.  Allow it to track
the latest releases rather than manually tracking them ourselves.

Signed-off-by: Benjamin Gilbert <bgilbert@cs.cmu.edu>

Author: bgilbert

builder/windows/Dockerfile

@@ -4,7 +4,6 @@ FROM docker.io/gentoo/stage3:latest
 # tarball
 RUN touch /etc/openslide-winbuild-builder-v3
 RUN echo 'FEATURES="-sandbox -usersandbox -ipc-sandbox -network-sandbox -pid-sandbox"' >> /etc/portage/make.conf
-COPY package.accept_keywords /etc/portage/package.accept_keywords/cross
 COPY package.use /etc/portage/package.use/cross
 RUN mkdir -p /var/db/repos/crossdev/{profiles,metadata} && echo crossdev > /var/db/repos/crossdev/profiles/repo_name && echo 'masters = gentoo' > /var/db/repos/crossdev/metadata/layout.conf && chown -R portage:portage /var/db/repos/crossdev
 COPY repos.conf /etc/portage/repos.conf/crossdev.conf