Remove unneeded detail on "format"

This was just duplicating info from the JSON Schema spec.

Co-authored-by: Darrel <darrmi@microsoft.com>

versions/3.1.0.md

@@ -153,7 +153,7 @@ However, to support documentation needs, the `format` property is an open `strin
 Additional formats MAY be used even though undefined by either JSON Schema or this specification.
 Types that are not accompanied by a `format` property follow the type definition in the JSON Schema. Tools that do not recognize a specific `format` MAY default back to the `type` alone, as if the `format` is not specified.
 
-Note that by default, JSON Schema validators MUST NOT attempt to validate the `format` keyword.  It is primarily treated as an annotation that informs applications of the intended nature of the data.  For historical reasons, it is possible to configure JSON Schema validators to validate `format`, but this is not consistently implemented and SHOULD NOT be relied upon in any environment where an unknown validator or unknown validator configuration might be used.
+Note that by default, JSON Schema validators will not attempt to validate the `format` keyword.  https://json-schema.org/draft/2019-09/release-notes.html#format-vocabulary
 
 The formats defined by the OAS are: