Remove sqlDatasourceDatabaseSelection feature toggle (#109391)

* Remove `sqlDatasourceDatabaseSelection` feature toggle

* Update e2e tests

docs/sources/datasources/mysql/query-editor/_index.md

@@ -70,7 +70,7 @@ Grafana’s query editors are unique for each data source. For general informati
 The MySQL query editor is located on the [Explore page](ref:explore). You can also access the MySQL query editor from a dashboard panel. Click the ellipsis in the upper right of the panel and select **Edit**.
 
 {{< admonition type="note" >}}
-If a default database is configured in the **Data Source Configuration page**, or via a provisioning configuration file, users will be restricted to querying only that pre-configured database. This feature is behind a feature flag and is available once you enable `sqlDatasourceDatabaseSelection`.
+If a default database is configured in the **Data Source Configuration page**, or via a provisioning configuration file, users will be restricted to querying only that pre-configured database.
 {{< /admonition >}}
 
 ## MySQL query editor components

docs/sources/setup-grafana/configure-grafana/feature-toggles/index.md

@@ -90,7 +90,6 @@ Most [generally available](https://grafana.com/docs/release-life-cycle/#general-
 | `refactorVariablesTimeRange`      | Refactor time range variables flow to reduce number of API calls made when query variables are chained |
 | `faroDatasourceSelector`          | Enable the data source selector within the Frontend Apps section of the Frontend Observability         |
 | `enableDatagridEditing`           | Enables the edit functionality in the datagrid panel                                                   |
-| `sqlDatasourceDatabaseSelection`  | Enables previous SQL data source dataset dropdown behavior                                             |
 | `reportingRetries`                | Enables rendering retries for the reporting feature                                                    |
 | `externalServiceAccounts`         | Automatic service account and token setup for plugins                                                  |
 | `cloudWatchBatchQueries`          | Runs CloudWatch metrics queries as separate batches                                                    |