Set airflow user password in DDL from environment

[AetherUnbound]

Current Situation

Our current DDL implementation uses the default password airflow always: https://github.com/WordPress/openverse-catalog/blob/d5d39f1ab65a7f3fcf72b04efa336bedd2c690a5/docker/local_postgres/0001_airflow_user_db.sql.
This can cause a potential security issue when deploying a production instance for the first time.

Suggested Improvement

Alter the first script to pull the password from an environment variable (possible solution here).

Benefit

This would allow us to define a different environment variable when running this migration on production, with a default for when running on dev.

Alternatives

Add explicit warnings in documentation or a guide for how to run deployments.

Additional context

This will be influenced and possibly covered by #1836.

Implementation

• 🙋 I would be interested in implementing this feature.