chore: Remove 'Run instrumentation tests' section from Contribution Guide

[jvh-aws]

• PR title and description conform to Pull Request guidelines.

Issue #, if available:

Description of changes: Remove outdated 'Run instrumentation tests' section from Contribution Guide

How did you test these changes? n/a

Documentation update required?

• No
• Yes (Please include a PR link for the documentation update)

General Checklist
- [ ] Added Unit Tests
- [ ] Added Integration Tests
- [ ] Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)

• Ensure commit message has the appropriate scope (e.g fix(storage): message, feat(auth): message, chore(all): message)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.77%. Comparing base (7a084cd) to head (5fb9624).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3172      +/-   ##
==========================================
- Coverage   54.78%   54.77%   -0.02%     
==========================================
  Files        1048     1048              
  Lines       31329    31329              
  Branches     4690     4690              
==========================================
- Hits        17165    17161       -4     
- Misses      12356    12358       +2     
- Partials     1808     1810       +2     

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