Change worker_version to int job_runner_version
According to conversation on https://github.com/huggingface/datasets-server/pull/912, worker_version needs to be an int value.
I renamed worker_version to job_runner_version as suggested in a comment in https://github.com/huggingface/datasets-server/blob/main/services/worker/src/worker/job_runner.py#L315 to keep consistency between class name and field.

Change worker_version to int job_runner_version: According to conversation on https://github.com/huggingface/datasets-server/pull/912, worker_version needs to be an int value.
I renamed worker_version to job_runner_version as suggested in a comment in https://github.com/huggingface/datasets-server/blob/main/services/worker/src/worker/job_runner.py#L315 to keep consistency between class name and field.
