fix subconcepts sorted error

[rayondemiel]

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Description of Change

When trying to export a thesaurus, I had a type problem concerning an entity whose natural_keys was perceived for another type (integer) because of it naming. It was therefore possible to sorted. This little fix seems to solve the problem by typing the concept's natural keys as string.

Issues Solved

Checklist

• I targeted one of these branches:
  • dev/8.0.x (under development): features, bugfixes not covered below
  • dev/7.6.x (main support): regressions, crashing bugs, security issues, major bugs in new features
  • dev/6.2.x (extended support): major security issues, data loss issues
• I added a changelog in arches/releases
• I submitted a PR to arches-docs (if appropriate)
• Unit tests pass locally with my changes
• I added tests that prove my fix is effective or that my feature works
• My test fails on the target branch

Accessibility Checklist

Developer Guide

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Ticket Background

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• Found by: @
• Tested by: @
• Designed by: @

Further comments

[jacobtylerwalls]

Hi @rayondemiel 👋

The tests didn't run on your PR because the formatting step failed. You can install the project's pre-commit hooks to get certain formatting and linting fixes applied automatically next time, see more here.

Would you mind cleaning up the formatting issue? Thanks.