Remove usage of referenced_tables in metadata.yaml

[scholtzan]

We used to use dryrun to get all tables a query references. This caused problems for queries that were referencing tables dryrun didn't have permissions to access. So we added referenced_tables to use the explicitly referenced tables instead of doing a dryrun and also to speed up the process for queries referencing main_v4.
We did make a change to use sqlglot to determine table dependencies. So it should be safe to remove referenced_tables and ignore them when generating Airflow DAGs.

┆Issue is synchronized with this Jira Task

[ANich]

Should we also remove referencedTables from the dry run cloud function and related utils too?

[scholtzan]

There are still a few edge cases where referenced_tables are used afaik.