Remove ruamel.yaml dependency.

[joaander]

Description

Remove ruamel.yaml dependency.

Motivation and Context

It is not used anywhere in the codebase.

Checklist:

• I am familiar with the Contributing Guidelines.
• I agree with the terms of the Contributor Agreement.
• My name is on the list of contributors.
• The changes introduced by this pull request are covered by existing or newly introduced tests.
• The package documentation and framework documentation in signac-docs are up to date with these changes.
• I have updated the changelog and added any related issue and pull request numbers for future reference.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (d23b336) 85.71% compared to head (7be64b6) 85.71%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #981   +/-   ##
=======================================
  Coverage   85.71%   85.71%           
=======================================
  Files          20       20           
  Lines        3466     3466           
  Branches      760      760           
=======================================
  Hits         2971     2971           
  Misses        337      337           
  Partials      158      158           

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[cbkerr]

Thanks!