(3/4) [Spike] [1h] Add and configure a Athena datasource in openscapes' grafana instance

[consideRatio]

This is task 3/4 in #4546, which is part of the big epic #4453.

Using the openscapes grafana UI at https://grafana.openscapes.2i2c.cloud/, add and configure an Athena datasource. This should be done using the grafana UI for now, relying on documentation at https://grafana.com/grafana/plugins/grafana-athena-datasource/.

The authentication should be using "AWS SDK Default", and the other configuration for the datasource needs to be figured out on the fly.

Definition of done

• [x] A datasource for Athena is created or already available
• [x] The datasource for Athena is configured:
  • with AWS SDK Default authentication
  • with options that you think makes sense after having considered them in a timeboxed amount of time
• [x] You've looked to see if grafana reports it to be healthy, and seen it either be reported as healthy, or not found such datasource health mechanism.

or

• [ ] You've tried to make it work up at most 1h without success, and then wrote a comment in this issue about it failing and optionally if you have ideas on why.

[GeorgianaElena]

With the changes in https://github.com/2i2c-org/infrastructure/pull/4619, the datasource now appears as healthy.