Performance regression when using API to populate dashboards across organizations (11.6.3 → 12.1.1)

### What happened? When using the Grafana API ([POST /api/dashboards/db](https://grafana.com/docs/grafana/latest/developers/http_api/dashboard/#create--update-dashboard)) to create/update dashboards across multiple organizations, we observed a **significant performance drop** after upgrading Grafana from `11.6.3` to `12.1.1`. We update dashboards in **batches of 100 organizations at a time**, which explains the rate of ~100 organisations/minute in 11.6.3. - **Grafana 11.6.3**: ~100 organisations/minute (≈30 min to populate 3000 Grafana organisations with dashboards) - **Grafana 12.1.1**: ~2 organisations/minute (over 24 hours for the same workload) Grafana does not return API errors, but the PostgreSQL backend logs constraint violations such as: ``` STATEMENT: INSERT INTO "dashboard_version" ... ERROR: duplicate key value violates unique constraint "UQE_dashboard_version_dashboard_id_version" DETAIL: Key (dashboard_id, version)=(8823, 71) already exists. ``` These database errors appear correlated with the slowdown. ### What did you expect to happen? Performance should remain consistent with previous versions (around 100 organisations/minute when populating dashboards across organizations) without hitting duplicate key errors in the database. ### Did this work before? Yes. The same test scenario worked correctly in Grafana `11.6.3`. The slowdown started after upgrading to Grafana `12.1.1`. ### How do we reproduce it? 1. Start with an empty Grafana instance. 2. Use the API to populate ~3000 organizations, each with: - 1 folder containing 10 dashboards. - Each dashboard applied across 50 versions (e.g., `dashboard_1` applied sequentially v1 → v50). - Apply updates in **batches of 100 organizations**. 3. Compare the population rate in Grafana `11.6.3` vs `12.1.1`. 4. Observe DB logs for duplicate key violations on the `dashboard_version` table. --- Additional information - **Hosting**: self-hosted Grafana, running on a VM. - **Resources*…