A dataset with "disabled" viewer has cache entries 
For example, the dataset https://huggingface.co/datasets/irds/neuclir_1_zh has disabled the viewer:

> The Dataset Viewer has been disabled on this dataset.

But we have entries in the database:

https://datasets-server.huggingface.co/splits?dataset=irds/neuclir_1_zh

```json
{
  "error": "The dataset tries to import a module that is not installed.",
  "cause_exception": "ImportError",
  "cause_message": "ir-datasets package missing; `pip install ir-datasets`",
  "cause_traceback": [
    "Traceback (most recent call last):\n",
    "  File \"/tmp/modules-cache/datasets_modules/datasets/irds--neuclir_1_zh/bb0b0253c1583dc19fc7decb4442fa2f8df4972ca05d8eccd8c5fdc2252851a2/neuclir_1_zh.py\", line 5, in <module>\n    import ir_datasets\n",
    "ModuleNotFoundError: No module named 'ir_datasets'\n",
    "\nDuring handling of the above exception, another exception occurred:\n\n",
    "Traceback (most recent call last):\n",
    "  File \"/src/services/worker/src/worker/job_runners/dataset/config_names.py\", line 55, in compute_config_names_response\n    for config in sorted(get_dataset_config_names(path=dataset, token=hf_token))\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/inspect.py\", line 360, in get_dataset_config_names\n    builder_cls = get_dataset_builder_class(dataset_module, dataset_name=os.path.basename(path))\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/load.py\", line 197, in get_dataset_builder_class\n    builder_cls = import_main_class(dataset_module.module_path)\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/load.py\", line 115, in import_main_class\n    module = importlib.import_module(module_path)\n",
    "  File \"/usr/local/lib/python3.9/importlib/__init__.py\", line 127, in import_module\n    return _bootstrap._gcd_import(name[level:], package, level)\n",
    "  File \"<frozen importlib._bootstrap>\", line 1030, in _gcd_import\n",
    "  File \"<frozen importlib._bootstrap>\", line 1007, in _find_and_load\n",
    "  File \"<frozen importlib._bootstrap>\", line 986, in _find_and_load_unlocked\n",
    "  File \"<frozen importlib._bootstrap>\", line 680, in _load_unlocked\n",
    "  File \"<frozen importlib._bootstrap_external>\", line 850, in exec_module\n",
    "  File \"<frozen importlib._bootstrap>\", line 228, in _call_with_frames_removed\n",
    "  File \"/tmp/modules-cache/datasets_modules/datasets/irds--neuclir_1_zh/bb0b0253c1583dc19fc7decb4442fa2f8df4972ca05d8eccd8c5fdc2252851a2/neuclir_1_zh.py\", line 7, in <module>\n    raise ImportError('ir-datasets package missing; `pip install ir-datasets`')\n",
    "ImportError: ir-datasets package missing; `pip install ir-datasets`\n"
  ]
}
```

It should have been deleted:
- by the webhook received from the Hub that tells that the dataset viewer has been disabled (hmmm: I think we don't receive that, in fact)
- by the daily backfill job (hmmm, I think we don't check if the dataset viewer is still enabled)
A dataset with "disabled" viewer has cache entries : For example, the dataset https://huggingface.co/datasets/irds/neuclir_1_zh has disabled the viewer:

> The Dataset Viewer has been disabled on this dataset.

But we have entries in the database:

https://datasets-server.huggingface.co/splits?dataset=irds/neuclir_1_zh

```json
{
  "error": "The dataset tries to import a module that is not installed.",
  "cause_exception": "ImportError",
  "cause_message": "ir-datasets package missing; `pip install ir-datasets`",
  "cause_traceback": [
    "Traceback (most recent call last):\n",
    "  File \"/tmp/modules-cache/datasets_modules/datasets/irds--neuclir_1_zh/bb0b0253c1583dc19fc7decb4442fa2f8df4972ca05d8eccd8c5fdc2252851a2/neuclir_1_zh.py\", line 5, in <module>\n    import ir_datasets\n",
    "ModuleNotFoundError: No module named 'ir_datasets'\n",
    "\nDuring handling of the above exception, another exception occurred:\n\n",
    "Traceback (most recent call last):\n",
    "  File \"/src/services/worker/src/worker/job_runners/dataset/config_names.py\", line 55, in compute_config_names_response\n    for config in sorted(get_dataset_config_names(path=dataset, token=hf_token))\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/inspect.py\", line 360, in get_dataset_config_names\n    builder_cls = get_dataset_builder_class(dataset_module, dataset_name=os.path.basename(path))\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/load.py\", line 197, in get_dataset_builder_class\n    builder_cls = import_main_class(dataset_module.module_path)\n",
    "  File \"/src/services/worker/.venv/lib/python3.9/site-packages/datasets/load.py\", line 115, in import_main_class\n    module = importlib.import_module(module_path)\n",
    "  File \"/usr/local/lib/python3.9/importlib/__init__.py\", line 127, in import_module\n    return _bootstrap._gcd_import(name[level:], package, level)\n",
    "  File \"<frozen importlib._bootstrap>\", line 1030, in _gcd_import\n",
    "  File \"<frozen importlib._bootstrap>\", line 1007, in _find_and_load\n",
    "  File \"<frozen importlib._bootstrap>\", line 986, in _find_and_load_unlocked\n",
    "  File \"<frozen importlib._bootstrap>\", line 680, in _load_unlocked\n",
    "  File \"<frozen importlib._bootstrap_external>\", line 850, in exec_module\n",
    "  File \"<frozen importlib._bootstrap>\", line 228, in _call_with_frames_removed\n",
    "  File \"/tmp/modules-cache/datasets_modules/datasets/irds--neuclir_1_zh/bb0b0253c1583dc19fc7decb4442fa2f8df4972ca05d8eccd8c5fdc2252851a2/neuclir_1_zh.py\", line 7, in <module>\n    raise ImportError('ir-datasets package missing; `pip install ir-datasets`')\n",
    "ImportError: ir-datasets package missing; `pip install ir-datasets`\n"
  ]
}
```

It should have been deleted:
- by the webhook received from the Hub that tells that the dataset viewer has been disabled (hmmm: I think we don't receive that, in fact)
- by the daily backfill job (hmmm, I think we don't check if the dataset viewer is still enabled)