[Discussion] Update tests or models for multiple `application_id` records for a given `opportunity_id`

### Is there an existing feature request for this?

- [X] I have searched the existing issues

### Describe the Feature

As of v0.6.0 and with our test data (will be provided in internal ticket), we sometimes have multiple `application_id` records associated with a given `opportunity_id`. This causes uniqueness test failures for `lever__opportunity_enhanced` and its upstream int models, which we should resolve.

### How would you implement this feature?

We need to determine if the model needs to be adjusted to ensure only one record per `opportunity_id` is created, or if we should update the combination of column tests to add `application_id`.

### Describe alternatives you've considered

_No response_

### Are you interested in contributing this feature?

- [ ] Yes.
- [ ] Yes, but I will need assistance.
- [ ] No.

### Anything else?

_No response_