fix coordmanager non associated coord

[ahmadtourei]

Description

This PR resolves issue #434 by ensuring that a patch with a non-associated coordinate can be accessed without any issues.

Thanks to @d-chambers for his help on this PR.

Checklist

I have (if applicable):

• referenced the GitHub issue this PR closes.
• documented the new feature with docstrings or appropriate doc page.
• included a test. See testing guidelines.
• your name has been added to the contributors page (docs/contributors.md).
• added the "ready_for_review" tag once the PR is ready to be reviewed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.84%. Comparing base (3858a11) to head (14a9d36).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #440   +/-   ##
=======================================
  Coverage   99.84%   99.84%           
=======================================
  Files         114      114           
  Lines        9170     9170           
=======================================
  Hits         9156     9156           
  Misses         14       14           

Flag	Coverage Δ
unittests	99.84% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

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