infra: remove cloudpickle constraint

[AbeCoull]

Issue #, if available:

Description of changes:
aws/sagemaker-python-sdk#4950

SM no longer constrains cloud-pickle

Testing done:

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (a5f3fe7) to head (b49d3fd).
Report is 39 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1063   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          135       135           
  Lines         9087      9087           
  Branches      1046      1046           
=========================================
  Hits          9087      9087           

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[rmshaffer]

[edit]

[rmshaffer]

Holding my approval temporarily while we look at any possible downstream impacts to jobs containers.

[rmshaffer]

@AbeCoull I suggest we close this PR for now, unless we have a particular scenario that is blocked? Keeping the version pinned I think reduces our possible test matrix slightly.