fix: Add CMH to the non-P3 list

[mufaddal-rohawala]

Issue #, if available:

Description of changes:
Add CMH to the non-P3 list
Low p3 availability in CMH has caused failures in pipeline release.

Testing done:

Merge Checklist

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[codecov-commenter]

Codecov Report

Merging #2904 (bb35ccd) into dev (c437191) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #2904   +/-   ##
=======================================
  Coverage   89.49%   89.49%           
=======================================
  Files         195      195           
  Lines       16567    16567           
=======================================
  Hits        14826    14826           
  Misses       1741     1741           

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[sagemaker-bot]

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• CodeBuild project: sagemaker-python-sdk-unit-tests
• Commit ID: bb35ccd
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• CodeBuild project: sagemaker-python-sdk-local-mode-tests
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AWS CodeBuild CI Report

• CodeBuild project: sagemaker-python-sdk-slow-tests
• Commit ID: bb35ccd
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