Add OpenAPI 3.1 support to Interactive API docs
Release notes
Add support for OAS 3.1 for the Interactive API Documentation.
Problem to solve
Partial support for OAS 3.1 was added for DAST in #327268 (closed), but the addition doesn't seem to work for all systems.
Proposal
Additional support for the current OpenAPI spec version will allow for more robust schemas and keep Gitlab implementation up to date with the current version of the specification.
Intended users
Feature Usage Metrics
As this is just adding support in an existing feature, we should be able to just use existing tracking/usage metrics.