Add dockerfile linting #522

Job	Run time
Linting	6s
Test Windows (3.6)	1m 5s
Test Windows (3.7)	1m 8s
Test Windows (3.8)	1m 11s
Test Windows (3.9)	40s
Test Windows (3.13)	43s
Lint Dockerfiles (Dockerfile-fedora32)	8s
Test Windows (3.10)	55s
Lint Dockerfiles (Dockerfile-fedora36)	7s
Lint Dockerfiles (Dockerfile-fuzz)	9s
Test (python3.4)	13s
Lint Dockerfiles (Dockerfile-fedora38)	8s
Lint Dockerfiles (Dockerfile-fedora30)	8s
Lint Dockerfiles (Dockerfile-fedora34)	10s
Test Windows (3.12)	58s
Test Windows (2.7)	1m 8s
Lint Dockerfiles (Dockerfile-fedora28)	6s
Test (python2.7)	11s
Lint Dockerfiles (Dockerfile-fedora40)	10s
Test (python3.5)	13s
Test Windows (3.11)	37s
Test (python3.3)	16s
Test (python3.6)	12s
Test (python3.13)	24s
Test (pypy)	12s
Test (python3.9)	21s
Test (python3.10)	24s
Test (python3.11)	22s
Test (python3.7)	13s
Test (python3.12)	22s
Test (pypy3)	11s
Test (python3.8)	12s
	13m 23s

Provide feedback