Create and drop indexes following mongodb atlas recommendations
https://cloud.mongodb.com/v2/6239e2417155de3d798e9187#metrics/replicaSet/6239e8ba6c32bf5c2d888fb5/advisor/createIndexes

Recommends to create an index on datasets_server_queue.split_jobs

```
status: 1
created_at: 1
```

And to drop three redundant indexes:

- datasets_server_queue.split_jobs

```
dataset_name: 1
config_name: 1
split_name: 1
```

- datasets_server_queue.dataset_jobs

```
dataset_name: 1
```

- datasets_server_cache.splits

```
status: 1
```

Note that I already manually deleted these three indexes though Mongo Atlas, and that they are not defined in the code explicitly:
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L91
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L120-L124
- https://github.com/huggingface/datasets-server/blob/main/libs/libcache/src/libcache/cache.py#L118-L122

But they were created again, which means that in some way `mongorestore` must be the one that creates them automatically. Possibly because they correspond to the primary key:
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L110-L111
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L147-L148

No idea why an index for "status" is created in datasets_server_cache.splits:
- https://github.com/huggingface/datasets-server/blob/main/libs/libcache/src/libcache/cache.py#L92)
Create and drop indexes following mongodb atlas recommendations: https://cloud.mongodb.com/v2/6239e2417155de3d798e9187#metrics/replicaSet/6239e8ba6c32bf5c2d888fb5/advisor/createIndexes

Recommends to create an index on datasets_server_queue.split_jobs

```
status: 1
created_at: 1
```

And to drop three redundant indexes:

- datasets_server_queue.split_jobs

```
dataset_name: 1
config_name: 1
split_name: 1
```

- datasets_server_queue.dataset_jobs

```
dataset_name: 1
```

- datasets_server_cache.splits

```
status: 1
```

Note that I already manually deleted these three indexes though Mongo Atlas, and that they are not defined in the code explicitly:
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L91
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L120-L124
- https://github.com/huggingface/datasets-server/blob/main/libs/libcache/src/libcache/cache.py#L118-L122

But they were created again, which means that in some way `mongorestore` must be the one that creates them automatically. Possibly because they correspond to the primary key:
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L110-L111
- https://github.com/huggingface/datasets-server/blob/main/libs/libqueue/src/libqueue/queue.py#L147-L148

No idea why an index for "status" is created in datasets_server_cache.splits:
- https://github.com/huggingface/datasets-server/blob/main/libs/libcache/src/libcache/cache.py#L92)