add breaking change information about form_data datasource_type (apac…

…he#20321)

UPDATING.md

@@ -31,10 +31,10 @@ assists people when migrating to a new version.
 
 ### Breaking Changes
 
-- [19770](https://github.com/apache/superset/pull/19770): As per SIPs 11 and 68, the native NoSQL Druid connector is deprecated and has been removed. Druid is still supported through SQLAlchemy via pydruid. The config keys `DRUID_IS_ACTIVE` and `DRUID_METADATA_LINKS_ENABLED` have also been removed.
+- [19981](https://github.com/apache/superset/pull/19981): Per [SIP-81](https://github.com/apache/superset/issues/19953) the /explore/form_data api now requires a `datasource_type` in addition to a `datasource_id` for POST and PUT requests
+- [19770](https://github.com/apache/superset/pull/19770): Per [SIP-11](https://github.com/apache/superset/issues/6032) and [SIP-68](https://github.com/apache/superset/issues/14909), the native NoSQL Druid connector is deprecated and has been removed. Druid is still supported through SQLAlchemy via pydruid. The config keys `DRUID_IS_ACTIVE` and `DRUID_METADATA_LINKS_ENABLED` have also been removed.
 - [19274](https://github.com/apache/superset/pull/19274): The `PUBLIC_ROLE_LIKE_GAMMA` config key has been removed, set `PUBLIC_ROLE_LIKE = "Gamma"` to have the same functionality.
 - [19273](https://github.com/apache/superset/pull/19273): The `SUPERSET_CELERY_WORKERS` and `SUPERSET_WORKERS` config keys has been removed. Configure Celery directly using `CELERY_CONFIG` on Superset.
-- [19262](https://github.com/apache/superset/pull/19262): Per [SIP-11](https://github.com/apache/superset/issues/6032) and [SIP-68](https://github.com/apache/superset/issues/14909) the native NoSQL Druid connector is deprecated and will no longer be supported. Druid SQL is still [supported](https://superset.apache.org/docs/databases/druid).
 - [19231](https://github.com/apache/superset/pull/19231): The `ENABLE_REACT_CRUD_VIEWS` feature flag has been removed (premantly enabled). Any deployments which had set this flag to false will need to verify that the React views support their use case.
 - [19230](https://github.com/apache/superset/pull/19230): The `ROW_LEVEL_SECURITY` feature flag has been removed (permantly enabled). Any deployments which had set this flag to false will need to verify that the presence of the Row Level Security feature does not interfere with their use case.
 - [19168](https://github.com/apache/superset/pull/19168): Celery upgrade to 5.X resulted in breaking changes to its command line invocation. Please follow [these](https://docs.celeryq.dev/en/stable/whatsnew-5.2.html#step-1-adjust-your-command-line-invocation) instructions for adjustments. Also consider migrating you Celery config per [here](https://docs.celeryq.dev/en/stable/userguide/configuration.html#conf-old-settings-map).