#1112 remove top-level connections, fix some import warnings

[gabrielwol]

What this pull request accomplishes:

• Removes top level database connections in 3 dags
• schedule_interval -> schedule deprecation warning
• fixes for many other Airflow deprecation warnings
• adjust pytest to include warnings
  • I tried upgrading env_canada to latest version to remove a deprecation warning, and then it downgraded google provider to 8.3 (2022). I wasn't comfortable with this so I backtracked on failing on warnings, but the only one remaining is about an env_canada which is about 50 less than before!

Issue(s) this solves:

• Closes Airflow: Remove top level connection retrievals in 4 DAGs #1112, test_dags action only capturing errors and not warnings #1115

What, in particular, needs to reviewed:

What needs to be done by a sysadmin after this PR is merged

• I checked out this branch in /data/airflow/data_scripts to test the many DAG changes, we should revert to master