Pulp

Adds additional d_artifact.remote check

Not all d_artifact objects have remotes, e.g. the migration plugin does not. Other places in the code account for this, but there is one area that does not. This adds an additional check to one codepath that checks for equality of d_artifact.remote.pk only if d_artifact.remote exists.

backports #7876 https://pulp.plan.io/issues/7876 re #8485 https://pulp.plan.io/issues/8485

(cherry picked from commit 25745275c0f3a7bd832946749ed27381694d612f)

Fixed artifact_stages edge case for multi-artifact/multi-remote batches.

Only encountered when 2to3-migrating specific content in specific orders.

backports #8377 https://pulp.plan.io/issues/8377 re #8485 https://pulp.plan.io/issues/8485

(cherry picked from commit b23c9294b9ed555078053b4968ed5b933ab1e9c9)

Teach artifact_stages:_needed_remote_artifacts() to not return dupes.

backports #8489 https://pulp.plan.io/issues/8489 closes #8485 https://pulp.plan.io/issues/8485

(cherry picked from commit 47e5cc2a69464caaefbb50f994de03d72fb780e4)