Add start and end time to info.json

[asmacdo]

Fixes #193

This does not need a schema bump, so long as this is merged for the same release as #200

Its not pretty:

    "start_time": 1728506948.210715,
    "end_time": 1728506949.2119823

Full info.json

{
  "command": "sleep 1",
  "system": {
    "cpu_total": 20,
    "memory_total": 33336131584,
    "hostname": "fancy",
    "uid": 1000,
    "user": "austin"
  },
  "env": {},
  "gpu": null,
  "duct_version": "0.5.0",
  "schema_version": "0.1.1",
  "execution_summary": {
    "exit_code": 0,
    "command": "sleep 1",
    "logs_prefix": "Z_",
    "wall_clock_time": 1.0012671947479248,
    "peak_rss": 1896448,
    "average_rss": 1896448.0,
    "peak_vsz": 232374272,
    "average_vsz": 232374272.0,
    "peak_pmem": 0.0,
    "average_pmem": 0.0,
    "peak_pcpu": 0.0,
    "average_pcpu": 0.0,
    "num_samples": 9,
    "num_reports": 2,
    "start_time": 1728506948.210715,
    "end_time": 1728506949.2119823
  },
  "output_paths": {
    "stdout": "Z_stdout",
    "stderr": "Z_stderr",
    "usage": "Z_usage.json",
    "info": "Z_info.json",
    "prefix": "Z_"
  }
}

But sticking with the theme of keeping info.json machine readable, I've opted not to do something like

end_time = datetime.utcfromtimestamp(data['end_time']).strftime('%Y-%m-%d %H:%M:%S')

If we want that it can be done in a renderer.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.00%. Comparing base (af1167d) to head (7f2bc77).
Report is 11 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #201      +/-   ##
==========================================
- Coverage   94.17%   94.00%   -0.18%     
==========================================
  Files           2        2              
  Lines         567      567              
  Branches       88       65      -23     
==========================================
- Hits          534      533       -1     
- Misses         21       22       +1     
  Partials       12       12              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.