fix(ingest/looker): stop emitting tag owner

[sgomezvillamor]

This is removing the datahub owner for the Measure, Dimension and Temporal tags emitted by Looker and LookML source connectors.

Looker connector is too much opinionated on the ownership of these tags and not aligned with how other connectors work, which just emit the tag with no owner.

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[hsheth2]

LGTM

[hsheth2]

There's a small lint failure, but we'll be able to merge once that's fixed

+ flake8 --count --statistics src/ tests/ examples/
Skipped 1 files
src/datahub/ingestion/source/looker/looker_common.py:78:1: F401 'datahub.metadata.schema_classes.OwnerClass' imported but unused
src/datahub/ingestion/source/looker/looker_common.py:78:1: F401 'datahub.metadata.schema_classes.OwnershipClass' imported but unused
src/datahub/ingestion/source/looker/looker_common.py:78:1: F401 'datahub.metadata.schema_classes.OwnershipTypeClass' imported but unused
3     F401 'datahub.metadata.schema_classes.OwnerClass' imported but unused
3

> Task :metadata-ingestion:lint FAILED