docs: Update UPDATING.md regarding potential breaking change to `ab_u…

…ser.email` column (apache#25115)

Co-authored-by: Michael S. Molina <[email protected]>

UPDATING.md

@@ -24,6 +24,7 @@ assists people when migrating to a new version.
 
 ## Next
 
+- [25053](https://github.com/apache/superset/pull/25053): Extends the `ab_user.email` column from 64 to 320 characters which has an associated unique key constraint. This will problematic for MySQL metadata databases which use the InnoDB storage engine with the  `innodb_large_prefix` parameter disabled as the key prefix limit is 767 bytes. Enabling said parameter and ensuring that the table uses either the use the `DYNAMIC` or `COMPRESSED` row format should remedy the problem. See [here](https://dev.mysql.com/doc/refman/5.7/en/innodb-limits.html) for more details.
 - [24939](https://github.com/apache/superset/pull/24939): Augments the foreign key constraints for the `embedded_dashboards` table to include an explicit CASCADE ON DELETE to ensure the relevant records are deleted when a dashboard is deleted. Scheduled downtime may be advised.
 - [24938](https://github.com/apache/superset/pull/24938): Augments the foreign key constraints for the `dashboard_slices` table to include an explicit CASCADE ON DELETE to ensure the relevant records are deleted when a dashboard or slice is deleted. Scheduled downtime may be advised.
 - [24911](https://github.com/apache/superset/pull/24911): Changes the column type from `TEXT` to `MediumText` in table `logs`, potentially requiring a table lock on MySQL dbs or taking some time to complete on large deployments.

docs/docs/installation/configuring-superset.mdx

@@ -106,7 +106,7 @@ Superset supports the following database engines/versions:
 | Database Engine                                           | Supported Versions                 |
 | --------------------------------------------------------- | ---------------------------------- |
 | [PostgreSQL](https://www.postgresql.org/)                 | 10.X, 11.X, 12.X, 13.X, 14.X, 15.X |
-| [MySQL](https://www.mysql.com/)                           | 5.X                                |
+| [MySQL](https://www.mysql.com/)                           | 5.7, 8.X                           |
 
 
 Use the following database drivers and connection strings: