Ash.Policy.Authorizer returns records denied by a runtime read policy to any actor

Incorrect Authorization vulnerability in ash-project ash returns records that a runtime read policy denies to any actor.

When a resource has an access_type :runtime read policy (a check evaluated per record rather than compiled to a filter), Ash.Policy.Authorizer decides each record in check_result/1 (lib/ash/policy/authorizer/authorizer.ex) by discarding impossible policy scenarios and inspecting what remains. When every scenario for a record was impossible, meaning no policy can authorize it and it must be forbidden, the empty-scenario branch instead kept the record ({[record | data], authorizer, any_forbidden?}) and returned it as authorized. As a result, records the runtime read policy denies are returned to any actor. The fix forbids a record whose scenarios are all impossible.

This issue affects ash: from 3.4.44 before 3.32.2.