test-docker-py: remove comment about docker 17.06 limitations

Our dev-container now has buildx installed, so we're no longer
limited to 17.06.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 79a0f82ca1898b62cd4791bf0991ab04d68a8927)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/make/test-docker-py

@@ -4,9 +4,6 @@ set -e
 source hack/make/.integration-test-helpers
 
 # The commit or tag to use for testing
-# TODO docker 17.06 cli client used in CI fails to build using a sha;
-# unable to prepare context: unable to 'git clone' to temporary context directory: error fetching: error: no such remote ref ead0bb9e08c13dd3d1712759491eee06bf5a5602
-#: exit status 128
 : "${DOCKER_PY_COMMIT:=5.0.3}"
 
 # The version (and variant) of the python image to use for the tests;