Raise pulpcore requirement to 3.55+

[hstct]

closes #1100

[mdellweg]

Oh, I think you are in for a search and replace session. e.g. artifacts_api_client is now pulpcore_bindings.ArtifactsApi.

I used this scriptlet:

find . -name "*.py" -exec sed -i \
-e 's/content_api_client/pulpcore_bindings.ContentApi/' \
-e 's/artifacts_api_client/pulpcore_bindings.ArtifactsApi/' \
-e 's/upstream_pulp_api_client/pulpcore_bindings.UpstreamPulpsApi/' \
\{\} +

But you need to adjust the fixture calling in the function headers by hand.