feat: set default image tags of Dagster provided images in Helm chart to current Chart version

Summary:
Resolves https://github.com/dagster-io/dagster/issues/4229.

For images in the Helm chart that default to a Dagster provided image, the tag is now null.
We now use .Chart.Version to populate the value of this tag if it is null.

Test Plan:
pytest
integration

Reviewers: jordansanders, sidkmenon, johann

Reviewed By: johann

Differential Revision: https://dagster.phacility.com/D8301