perf(cache): avoid caching jobs when the cache is disabled (#435)

[mdonadoni]

Closes #422

Before

After

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (42622fa) 46.46% compared to head (553468f) 46.02%.

Additional details and impacted files

[](https://app.codecov.io/gh/reanahub/reana-job-controller/pull/435?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub) ```diff @@ Coverage Diff @@ ## master #435 +/- ## ========================================== - Coverage 46.46% 46.02% -0.44% ========================================== Files 17 17 Lines 1231 1234 +3 ========================================== - Hits 572 568 -4 - Misses 659 666 +7 ``` | [Files](https://app.codecov.io/gh/reanahub/reana-job-controller/pull/435?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub) | Coverage Δ | | |---|---|---| | [reana\_job\_controller/config.py](https://app.codecov.io/gh/reanahub/reana-job-controller/pull/435?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub#diff-cmVhbmFfam9iX2NvbnRyb2xsZXIvY29uZmlnLnB5) | `100.00% <100.00%> (ø)` | | | [reana\_job\_controller/job\_manager.py](https://app.codecov.io/gh/reanahub/reana-job-controller/pull/435?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub#diff-cmVhbmFfam9iX2NvbnRyb2xsZXIvam9iX21hbmFnZXIucHk=) | `78.33% <100.00%> (-11.33%)` | :arrow_down: |