Review and unify many (public) Astronomer repos related to Cosmos

[tatiana]

Context

Currently, we have many Cosmos-related repos within the Astronomer org. We should review them and try to unify them where possible.

The current situation is not manageable. It's not feasible to manage so many repos and keep them up-to-date, together with the other responsibilities of the OSS Integrations Team.

As an example, currently we're duplicating tutorials, splitting files referenced by the astronomer-cosmos repo in the cosmos-example, and we're not managing to review/keep them up-to-date:
#1153 (comment)

More details:

• astronomer-cosmos: The main repo, where the main code, unit tests, integration tests, and sample DAGs that are run in our CI when the code changes

Other public repos:

• cosmos-example
• cosmos-use-case
• cosmos-load-test
• airflow-wandb-cosmos-demo
• cosmos-dev - it's archived but still public. Should we start deleting repos?
• cosmos-demo
• airflow-summit-2024-cosmos

Internal/Private repos:

• field-cosmos-demo
• cosmos-dags

Acceptance criteria

• Analyse the existing repos
• Decide on what we want to keep and what can be archived/deleted/unified
• Arhive/delete or talk to the relevant stakeholders so actions can be taken