Circular reference in OpenAPI spec causes a stack overflow

### tfplugingen-openapi CLI version

tfplugingen-openapi module: v0.3.0

### OpenAPI Spec File

```YAML
https://gist.github.com/umeshkumhar/97c7888fbcf6f294bb54210e0faec918
```

### Generator Config

```YAML
provider:
name: backupdr

resources:
slp:
create:
path: /slp
method: POST
read:
path: /slp
method: GET
```

### Expected Behavior

It should have generated provider spec json.

### Actual Behavior

This just executed and later on get killed due to OOM (i guess). in some iteration it shows stack overflow error. The activity monitor states that it consumes 70+GB memory, please find the attached screenshot below. Seems like its failing during Marshalling the openapi file.

### Additional Information

Please suggest some workaround this.. if we can still generate some provider spec json for at least /slt, /sla, /slp. to kickstart.

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct