fix: report sub-minute job timeouts in seconds

[charan-rathore]

Summary

Job timeouts under a minute were printed as "0 minutes" because the message used integer division. A 3 second timeout now reads "3 seconds". Fixes #9527.

Changes

• Add a small format_timeout helper in job_runner.py that reports seconds below 60 and minutes otherwise.
• Use it at all three places that print the timeout.
• Add test_format_timeout.py (8 formatter cases) and an assertion in test_job_flow.py that a real 3 second job prints the timeout in seconds.

Testing

• The new job-flow assertion fails on the base commit and passes with the change.
• Full syft-job suite: 123 tests pass. The repo pre-commit hooks pass on the three changed files.
• Not run: the root all-package test suite and mypy.
• These results come from the person who prepared the change; I did not rerun them.
• fix: validate configured job timeout. #9526 and fix: enforce streaming job timeouts for partial output #9529 also edit job_runner.py (different problems), so one of us may need a small rebase around the imports.

Asana task

N/A, external contribution.

[charan-rathore]

Closing since this has sat without activity. Glad to reopen if someone wants to take it forward.