Unexpected naming conflict 
### Summary

> Error: A naming conflict has occurred - two entities have tried to define the same key 'subscriptionTypeBySubscriptionType'.…

### Steps to reproduce

```
CREATE TABLE subscription_types (
    subscription_type text PRIMARY KEY
);

CREATE TABLE subscription_pricing (
    subscription_type text REFERENCES subscription_types(subscription_type)
);

comment on table subscription_pricing is E'
@omit create,update,delete
';
```

### Expected results

No warning while generating schema

### Actual results

```
  graphile-build:warn Recoverable error occurred: Error: A naming conflict has occurred - two entities have tried to define the same key 'subscriptionTypeBySubscriptionType'.

  The first entity was:

    Adding field to GraphQL type 'SubscriptionPricing' for singular relation 'subscriptionTypeBySubscriptionType'

  The second entity was:

    Adding field to GraphQL type 'SubscriptionPricing' for singular relation 'subscriptionTypesByMySubscriptionType'.
```

### Additional context

Crystal @ 0f74d9b0452c600e25ec2db62edc90adedc2091b

```
export default  {
    extends: [PostGraphileAmberPreset],
    pgServices: [
		makePgService({
			connectionString: process.env.DATABASE_URL,
			schemas: ['public'],
		}),
	],

}
```