Update cnf_conformance to v0.9.4

It removes all hacks bypassing a few former bugs (e.g. [1]) and adapts
to the new cnf-conformance result output logic.

It runs all workload tests as it's now proposed (k8s conformance
is already part of smoke) and select the latest coredns
cnf-conformance.yml taking latest helm repo changes into account.

It sets criteria 95 as all steps are considered as passed and a
overall result 100/105.

[1] https://github.com/cncf/cnf-conformance/issues/388

Change-Id: I95b7889b21b86961e7a1d0c84b13e0ae367cae44
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>