feat: 🎸 add an index to the jobs collection
proposed by mongo atlas

<img width="1121" alt="Capture d’écran 2023-03-03 à 10 08 30" src="https://user-images.githubusercontent.com/1676121/222680591-1b2d14f3-6a9d-4937-888b-cb6756ba04c8.png">

feat: 🎸 add an index to the jobs collection: proposed by mongo atlas

<img width="1121" alt="Capture d’écran 2023-03-03 à 10 08 30" src="https://user-images.githubusercontent.com/1676121/222680591-1b2d14f3-6a9d-4937-888b-cb6756ba04c8.png">
