[BUG] [JAVA] AbstractOpenApiSchema class generated even if generateModels is set to false

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

I want to skip the generation of the model and for this I set:

<properties>
    <openapi.generator.maven.plugin.generateModels>false</openapi.generator.maven.plugin.generateModels>
</properties>

setting just <generateModels>false</generateModels> doesn't work due to this open issue I guess. Anyway the model is not generated indeed but under generated-docs/orgs/mode/ there is still something inside: the AbstractOpenApiSchema class (which doesn't not compile due to this other issue.

openapi-generator version

6.3.0

Suggest a fix

The desidered behaviour is to have the model directory completely empty (or not generated at all).

Start with the Maven plugin setting for generateModels and trace how it produces AbstractOpenApiSchema under generated-docs/orgs/mode/. Reproduce the behavior with OpenAPI Generator 6.3.0, then verify that setting generateModels to false leaves the model directory empty or absent without generating AbstractOpenApiSchema.