ci: Add push trigger for docker-builds (#81228)
Adds a push trigger for the docker-builds workflow so that docker images
will be re-built when changes that affect docker-builds get pushed
Signed-off-by: Eli Uriegas <eliuriegas@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81228
Approved by: https://github.com/malfet
