Decrease worker size metrics when dataset is blocked
Part of https://github.com/huggingface/dataset-viewer/issues/2945
Context: https://github.com/huggingface/dataset-viewer/issues/2945#issuecomment-2192170023

- Decrease jobs when a dataset is blocked.
Decrease worker size metrics when dataset is blocked: Part of https://github.com/huggingface/dataset-viewer/issues/2945
Context: https://github.com/huggingface/dataset-viewer/issues/2945#issuecomment-2192170023

- Decrease jobs when a dataset is blocked.