Adds pip requirements file to nightly gpu ci image (apache#16472)

Author: perdasilva

ci/docker/Dockerfile.build.ubuntu_nightly_gpu

@@ -29,6 +29,7 @@ COPY install/deb_ubuntu_ccache.sh /work/
 RUN /work/deb_ubuntu_ccache.sh
 
 COPY install/ubuntu_python.sh /work/
+COPY install/requirements /work/
 RUN /work/ubuntu_python.sh
 
 COPY install/ubuntu_scala.sh /work/