fix type of change

Author: gewarren

docs/core/compatibility/9.0.md

@@ -39,7 +39,7 @@ If you're migrating an app to .NET 9, the breaking changes listed here might aff
 | [BinaryReader.GetString() returns "\uFFFD" on malformed sequences](core-libraries/9.0/binaryreader.md) | Behavioral change | Preview 7  |
 | [Creating type of array of System.Void not allowed](core-libraries/9.0/type-instance.md) | Behavioral change   | Preview 1          |
 | [Default `Equals()` and `GetHashCode()` throw for types marked with `InlineArrayAttribute`](core-libraries/9.0/inlinearrayattribute.md) | Behavioral change   | Preview 6          |
-| [EnumConverter validates registered types to be enum](core-libraries/9.0/enumconverter.md) | Binary incompatible | Preview 7          |
+| [EnumConverter validates registered types to be enum](core-libraries/9.0/enumconverter.md) | Behavioral change | Preview 7          |
 | [FromKeyedServicesAttribute no longer injects non-keyed parameter](core-libraries/9.0/non-keyed-params.md) | Behavioral change   | RC 1               |
 | [IncrementingPollingCounter initial callback is asynchronous](core-libraries/9.0/async-callback.md) | Behavioral change   | RC 1               |
 | [Inline array struct size limit is enforced](core-libraries/9.0/inlinearray-size.md) | Behavioral change   | Preview 1          |