[Bug]: unstable error message for additional properties

[number492]

Actual Behavior

When using the additional_properties_default_policy config option with the 'forbid' value, and multiple additional values are present, the error message lists the relevant properties in potentially different order every time.
Sorting errors at

openapi-core/openapi_core/validation/schemas/_validators.py

Line 79 in cbcd361

extras = set(find_additional_properties(instance, schema))

might solve this issue.

Expected Behavior

Error messages are deterministic.

Steps to Reproduce

See Actual Behavior.

OpenAPI Core Version

0.23.0

OpenAPI Core Integration

None

Affected Area(s)

Validation

References

No response

Anything else we need to know?

No response

Would you like to implement a fix?

None