Retire amendment fix1515

[pratikmankawde]

High Level Overview of Change

This change retires the fix1515 amendment.

Context of Change

Amendments activated for more than 2 years can be retired.

Type of Change

• Bug fix (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)
• Refactor (non-breaking change that only restructures code)
• Performance (increase or change in throughput and/or latency)
• Tests (you added tests for code that already exists, or your new feature included in this PR)
• Documentation update
• Chore (no impact to binary, e.g. .gitignore, formatting, dropping support for older tooling)
• Release

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.5%. Comparing base (5e33ca5) to head (1772bbd).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #5920     +/-   ##
=========================================
- Coverage     79.5%   79.5%   -0.0%     
=========================================
  Files          817     817             
  Lines        72210   72197     -13     
  Branches      8280    8273      -7     
=========================================
- Hits         57398   57380     -18     
- Misses       14812   14817      +5     

Files with missing lines	Coverage Δ
src/xrpld/app/paths/detail/BookStep.cpp	95.6% <100.0%> (+0.8%)	⬆️

... and 4 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[a1q123456]

LGTM

[a1q123456]

looks good! feel free to add a ready to merge label