Can't extract models from openapi via paths and references

[Wim-De-Clercq]

Describe the bug
When trying to extract models from openapi, where the main openapi schema itself does not contain traditional components/schemas it does not seem to behave correctly.
No models are found, or otherwise references don't get resolved properly.

To Reproduce

Example schema:
Please see the data in this commit Wim-De-Clercq/testingrepo@1c0c8e4

It has a little test as well, although nothing is truly asserted.

Expected behavior
I expect the schemas within ./cat/schemas.yaml to be turned into models.

Version:

• OS: Kubuntu 24.04
• Python version: 3.11
• datamodel-code-generator version: main branch.

Additional context
The test in my commit keeps on complaining about Models not found in the input data.

I actually come from a larger project and tried to reproduce it in a small test.
In my large project - with in my eyes a similar setup - I however end up with file not found errors. So I'm pretty sure the ref resolving has problems as well with this kind of setup. Somewhere beyond this test. But at the moment I keep on getting stuck on this error to try reproducing it further.