add ps to the docker image (interline needed this)

[mikemhenry]

Developers certificate of origin

• I certify that this contribution is covered by the MIT License here and the Developer Certificate of Origin at https://developercertificate.org/.

[mikemhenry]

Interline needed this for their perses image, so adding it to ours in case anyone else needs it

[mikemhenry]

Running docker build here:
https://github.com/OpenFreeEnergy/openfe/actions/runs/5624517175

[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (4ead173) 91.64% compared to head (d44807d) 91.64%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #501   +/-   ##
=======================================
  Coverage   91.64%   91.64%           
=======================================
  Files         110      110           
  Lines        6549     6549           
=======================================
  Hits         6002     6002           
  Misses        547      547           

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.