api: fix create_workflow_from_json to load workflow specification

[giuseppe-steduto]

Amend create_workflow_from_json so that the workflow specification is always loaded in the REANA specification that is passed to reana-server.

Closes #666.

[mdonadoni]

Snakemake tests are not passing on Python>=3.11 and need to be skipped, as done here: https://github.com/reanahub/reana-commons/blob/2efdd4f9c0d05cb0f7ba292d9a1eb9b70eb13692/tests/test_snakemake.py#L20-L23

Could you please update them so that the CI passes?

[codecov[bot]]

Codecov Report

Merging #675 (69acb62) into master (226eb7f) will increase coverage by 0.11%. The diff coverage is 100.00%.

Additional details and impacted files

[](https://app.codecov.io/gh/reanahub/reana-client/pull/675?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub) ```diff @@ Coverage Diff @@ ## master #675 +/- ## ========================================== + Coverage 58.51% 58.62% +0.11% ========================================== Files 24 24 Lines 2384 2388 +4 ========================================== + Hits 1395 1400 +5 + Misses 989 988 -1 ``` | [Files](https://app.codecov.io/gh/reanahub/reana-client/pull/675?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub) | Coverage Δ | | |---|---|---| | [reana\_client/api/client.py](https://app.codecov.io/gh/reanahub/reana-client/pull/675?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=reanahub#diff-cmVhbmFfY2xpZW50L2FwaS9jbGllbnQucHk=) | `45.54% <100.00%> (+0.77%)` | :arrow_up: |