fix(build): use busybox instead of scratch to copy build output

Author: AhmedAmrNabil

docker/Dockerfile.arch

@@ -30,5 +30,5 @@ RUN sed -i 's|source=.*|source=()|' PKGBUILD && \
     sed -i 's|git submodule.*||' PKGBUILD
 RUN makepkg --noconfirm  # no -s, deps already installed
 
-FROM scratch
+FROM busybox
 COPY --from=builder /home/builder/*.pkg.tar.zst /pkg-out/

docker/Dockerfile.fedora

@@ -14,5 +14,5 @@ RUN cpack --config build/CPackConfig.cmake -G RPM
 RUN mkdir rpm-out
 RUN cp /app/ArenaRush-*.rpm /app/rpm-out/
 
-FROM scratch
+FROM busybox
 COPY --from=builder /app/rpm-out/*.rpm /rpm-out/