Fix MongoDB CPU alerts
We get a lot of alerts about the CPU usage from the MongoDB server

The profiler shows a lot of queries on the `jobs` collections, that take about 400ms to complete. One of them is shown below:

<img width="950" alt="Capture d’écran 2023-11-13 à 11 51 42" src="https://github.com/huggingface/datasets-server/assets/1676121/1d2245be-f35b-4640-942a-a951ffb1a470">

```json
{
  "type": "command",
  "ns": "datasets_server_queue.jobsBlue",
  "command": {
    "find": "jobsBlue",
    "filter": {
      "difficulty": {
        "$lte": 40
      },
      "namespace": {
        "$nin": [
          "KoddaDuck",
          "nanakonoda"
        ]
      },
      "priority": "low",
      "status": "waiting"
    },
    "sort": {
      "created_at": 1
    },
    "projection": {
      "revision": 1,
      "priority": 1,
      "type": 1,
      "config": 1,
      "unicity_id": 1,
      "dataset": 1,
      "split": 1
    },
    "limit": 1,
    "singleBatch": true,
    "lsid": {
      "id": {
        "$binary": {
          "base64": "NwaDfCi0R9GeqxX+HKXHJw==",
          "subType": "04"
        }
      }
    },
    "$clusterTime": {
      "clusterTime": {
        "$timestamp": {
          "t": 1699837031,
          "i": 24
        }
      },
      "signature": {
        "hash": {
          "$binary": {
            "base64": "gQpN2CmhG+vXsXq0Kcctf3i8ZF8=",
            "subType": "00"
          }
        },
        "keyId": 7245135689732325000
      }
    },
    "$db": "datasets_server_queue"
  },
  "planSummary": "IXSCAN { priority: 1, status: 1, created_at: 1, namespace: 1 }",
  "keysExamined": 48364,
  "docsExamined": 48346,
  "fromMultiPlanner": true,
  "cursorExhausted": true,
  "numYields": 111,
  "nreturned": 1,
  "queryHash": "367AAECD",
  "planCacheKey": "6E15B095",
  "queryFramework": "classic",
  "reslen": 526,
  "locks": {
    "FeatureCompatibilityVersion": {
      "acquireCount": {
        "r": 112
      }
    },
    "Global": {
      "acquireCount": {
        "r": 112
      }
    },
    "Mutex": {
      "acquireCount": {
        "r": 1
      }
    }
  },
  "readConcern": {
    "level": "local",
    "provenance": "implicitDefault"
  },
  "storage": {},
  "remote": "192.168.253.254:14822",
  "protocol": "op_msg",
  "durationMillis": 418,
  "v": "6.0.11"
}
```
Fix MongoDB CPU alerts: We get a lot of alerts about the CPU usage from the MongoDB server

The profiler shows a lot of queries on the `jobs` collections, that take about 400ms to complete. One of them is shown below:

<img width="950" alt="Capture d’écran 2023-11-13 à 11 51 42" src="https://github.com/huggingface/datasets-server/assets/1676121/1d2245be-f35b-4640-942a-a951ffb1a470">

```json
{
  "type": "command",
  "ns": "datasets_server_queue.jobsBlue",
  "command": {
    "find": "jobsBlue",
    "filter": {
      "difficulty": {
        "$lte": 40
      },
      "namespace": {
        "$nin": [
          "KoddaDuck",
          "nanakonoda"
        ]
      },
      "priority": "low",
      "status": "waiting"
    },
    "sort": {
      "created_at": 1
    },
    "projection": {
      "revision": 1,
      "priority": 1,
      "type": 1,
      "config": 1,
      "unicity_id": 1,
      "dataset": 1,
      "split": 1
    },
    "limit": 1,
    "singleBatch": true,
    "lsid": {
      "id": {
        "$binary": {
          "base64": "NwaDfCi0R9GeqxX+HKXHJw==",
          "subType": "04"
        }
      }
    },
    "$clusterTime": {
      "clusterTime": {
        "$timestamp": {
          "t": 1699837031,
          "i": 24
        }
      },
      "signature": {
        "hash": {
          "$binary": {
            "base64": "gQpN2CmhG+vXsXq0Kcctf3i8ZF8=",
            "subType": "00"
          }
        },
        "keyId": 7245135689732325000
      }
    },
    "$db": "datasets_server_queue"
  },
  "planSummary": "IXSCAN { priority: 1, status: 1, created_at: 1, namespace: 1 }",
  "keysExamined": 48364,
  "docsExamined": 48346,
  "fromMultiPlanner": true,
  "cursorExhausted": true,
  "numYields": 111,
  "nreturned": 1,
  "queryHash": "367AAECD",
  "planCacheKey": "6E15B095",
  "queryFramework": "classic",
  "reslen": 526,
  "locks": {
    "FeatureCompatibilityVersion": {
      "acquireCount": {
        "r": 112
      }
    },
    "Global": {
      "acquireCount": {
        "r": 112
      }
    },
    "Mutex": {
      "acquireCount": {
        "r": 1
      }
    }
  },
  "readConcern": {
    "level": "local",
    "provenance": "implicitDefault"
  },
  "storage": {},
  "remote": "192.168.253.254:14822",
  "protocol": "op_msg",
  "durationMillis": 418,
  "v": "6.0.11"
}
```