Add support for using a ProtoV6Schema when implementing a list

### Module version

```
github.com/hashicorp/terraform-plugin-framework v1.17.0
```

### Relevant provider source code

```go
func (r *ListResource) RawV5Schemas(ctx context.Context, req list.RawV5SchemaRequest, resp *list.RawV5SchemaResponse) {
thingResource := ResourceVPC()

resp.ProtoV5Schema = thingResource.ProtoSchema(ctx)()
resp.ProtoV5IdentitySchema = thingResource.ProtoIdentitySchema(ctx)()
}
```

### Expected Behavior

When I'm developing a list resource with a provider that got ProtoV6Schemas defined everywhere, I would expect that when I'm looking at the documentation and implementing I got options to use a ProtoV6Schemas.

### Actual Behavior

At the moment I only got ProtoV5Schema offered when I'm looking at the documentation https://developer.hashicorp.com/terraform/plugin/sdkv2/resources/list, making our development on the list completly stuck.

It would also be helpful to show in the documentation examples on how to test list resources.

### Steps to Reproduce

- Trying to implement support for lists
- Reading the documentation
- stuck

### References

- https://developer.hashicorp.com/terraform/plugin/sdkv2/resources/list