[Bug]: Regression: class specified in @ArraySchema.schema.implementation not rendered in schemas

Description of the problem/issue

we are using Springdoc with the swagger-core dependency.
we were using @ArraySchema successfully in Springdoc 2.6 (default 3.0 openapi output from swagger) but once we moved to springdoc 2.8 (default 3.1 openapi output from swagger), the implementation class specified in @ArraySchema.schema is not rendered at all.
So the swagger UI fails with errors like:

"Resolver error at responses.200.content.*/*.schema.items.$ref
Could not resolve reference: Invalid object key "ThingAssignment" at position 2 in "/components/schemas/ThingAssignment": key not found in object"

Affected Version

2.2.36

Earliest version the bug appears in (if known): not known

Steps to Reproduce

See attached zip file with app and notes. (The sample uses 2.2.36 but I also tried 2.2.38 with the same failure)

Expected Behavior

Should render the ThingAssignment in the Schemas section and emit the reference to array of ThingAssignment for the consuming class (User.java in the sample).

Actual Behavior

(see notes from zip)
Emitted the array reference but does not render the implementation class schema (ThingAssignment)
In prior versions with 3.0 output format, it was working fine.

Logs / Stack Traces

no logs but see notes in zip for the emitted output.

Additional Context

• By overriding the output format from the default 3.1 to 3.0, the problem goes away. springdoc.api-docs.version=openapi_3_0
• This swagger-core issue looks related but not sure if it fixes the problem for this issue as well, and if so, when will the fix be released? https://github.com/swagger-api/swagger-core/issues/4679
• issue originally raised against springdoc:
  https://github.com/springdoc/springdoc-openapi/issues/3097

Checklist

• [ x] I have searched the existing issues and this is not a duplicate.
• [ x] I have provided sufficient information for maintainers to reproduce the issue.

Start with the attached sample and notes, especially User.java and the @ArraySchema usage referencing ThingAssignment. Compare the generated OpenAPI 3.1 output with the OpenAPI 3.0 output enabled by springdoc.api-docs.version=openapi_3_0, then review swagger-core issue 4679. Done means the 3.1 schemas include ThingAssignment and the consuming array reference resolves without Swagger UI errors.