Provisioning: Fix provisioning issues with legacy alerting and data source permissions

[IevaVasiljeva]

What is this feature?

Fixing a permission error when provisioning dashboards that contain legacy alerts on Grafana Cloud Pro, Cloud Advanced or Enterprise.

Why do we need this feature?

Dashboards with legacy alerts can't be provisioned without this fix.

Who is this feature for?

Users who use dashboard and alert provisioning on Grafana Cloud Pro, Cloud Advanced or Enterprise instances.

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[grafanabot]

Hello @IevaVasiljeva!
Backport pull requests need to be either:

• Pull requests which address bugs,
• Urgent fixes which need product approval, in order to get merged,
• Docs changes.

Please, if the current pull request addresses a bug fix, label it with the type/bug label.
If it already has the product approval, please add the product-approved label. For docs changes, please add the type/docs label.
If the pull request modifies CI behaviour, please add the type/ci label.
If none of the above applies, please consider removing the backport label and target the next major/minor release.
Thanks!