SM Checks: Select probes automatically

[julienduchesne]

Crossplane doesn't have datasources, so we have to specify probe IDs manually
This will allow us to specify a number of probes to be selected randomly

I've updated the basic examples so that they use this attribute. The advanced examples still use explicit probes

[github-actions]

In order to lower resource usage and have a faster runtime, PRs will not run Cloud tests automatically.
To do so, a Grafana Labs employee must trigger the cloud acceptance tests workflow manually.

[peterschretlen]

No objections to the change itself. Looks ok to me, though a comment:

I can see a case for making this simple when people don't care where the probes are located.

Usually there are some criteria around probe selection though: US only / Europe only; private probes only. Particular if customers have a mix of public and private probes, the random selection may not see much use, or we may see requests to limit it somehow to a subset.

[julienduchesne]

Usually there are some criteria around probe selection though: US only / Europe only; private probes only. Particular if customers have a mix of public and private probes, the random selection may not see much use, or we may see requests to limit it somehow to a subset.

The probes attribute keeps working the same as before, so users can select the probes as they wish with it