fix: remove unnecessary leadership guards in GrafanaCloudConfigRequirer

[ca-scribner]

Issue

Previously, GrafanaCloudConfigRequirer would only emit a cloud_config_* event on relation changed/broken if this unit is a leader. This caused issues with multi-unit deployments as described in #12.

Solution

Since GrafanaCloudConfigRequirer only reads the relation remote's application_data, there is no need for a leadership guard because non-leader units have permission to read this data. The current commit removes these guards.

Context

closes #12

Testing Instructions

See this grafana-agent patch for testing instructions

Release Notes

[PietroPasotti]

So I think the change is going in the right direction, as it's odd to emit custom events conditionally on leadership.
However, I was expecting to see some documentation changes? Is there nothing in the module docstring that we need to adjust to reflect the change? (if not, it was probably a bad doc and we should create an issue to improve the documentation)
Secondly, I was expecting to see some test for the new behaviour.
A couple of simple tests using Context.emitted_events to verify that the available/revoked events are emitted regardless of leadership would be great.

[ca-scribner]

Yep good points.

• re doc changes: there is no usage documentation for the library atm :D I've raised this as Add documentation for the grafana_cloud_integrator library #15
• re lack of testing:
  • the repo has no testing for this library. The Provider at least gets imported by the charm, but the Requirer is not even imported elsewhere. I've raised an issue for this as Add tests for grafana_cloud_integrator library #16
  • For this specific PR, I'll add tests as you suggested to capture the emitted events

[ca-scribner]

@PietroPasotti added some tests like you mentioned to assert the correct events are emitted

[PietroPasotti]

Thanks for the tests! On top of the missing assertions spotted by leon, the fixtures should be cleaned up a bit.
The rest looks good!

[Abuelodelanada]

I would merge it as is and address the comments made in the created issues.

Dismissing given Jose's review. I think everything is resolved, but if not we can update it after