[CAL-3898] bug: round robin + offer seats adds all

![image](https://github.com/calcom/cal.com/assets/8019099/43d94adb-1899-44f5-a28b-f0a104ebbbf6)

![image](https://github.com/calcom/cal.com/assets/8019099/068e7d1a-cd07-4d92-b139-d727093538c4)

![image](https://github.com/calcom/cal.com/assets/8019099/70754997-cd81-444d-908a-4ca63feb6063)

<sub>[CAL-3898](https://linear.app/calcom/issue/CAL-3898/bug-round-robin-offer-seats-adds-all)</sub>