Library panels not working with provisioned dashboards, fail with: Panel plugin not found: Name: "...", UID: "..."

**What happened**: Library panels used in provisioned dashboard are not loaded correctly  **What you expected to happen**: Library panels are loaded correctly in dashboards which are loaded from json and/or there is a documented way on how to provision library panels together with provisioned dashboards. **How to reproduce it (as minimally and precisely as possible)**: - create a dashboard - save it as provisioned dashboard - restart server so provisioned dashboard is loaded - add new panel with random data - click on the panel and click "Create library panel" in the menu - now save the json of the dashboard for updating the provisioned dashboard After restarting the server again I would expect the panel to be loaded correctly, but instead above error is displayed. Interestingly after I delete the ``` "libraryPanel": { ... }, ``` part in json, the panel works again as expected. **Anything else we need to know?**: **Environment**: - Grafana version: v8.4.3 - Data source type & version: happens with any datasource - OS Grafana is installed on: docker container - User OS & Browser: -- - Grafana plugins: none - Others: --