Deduplicate route status entries

[sjberman]

Problem: Due to a shared slice pointer, in certain scenarios we could get entries in the status list that don't belong there, and result in duplicate entries when writing the status to the route.

Solution: Copy the previous value before adding new entries, to avoid the shared slice.

Testing: Ran the benchmarking test and no longer saw the issue.

Closes #4249

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• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
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Release notes

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please add a brief note that summarizes the change.

Fix an issue where duplicate status entries could be written on routes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.13%. Comparing base (9d2bf35) to head (29033e6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4250      +/-   ##
==========================================
+ Coverage   86.11%   86.13%   +0.01%     
==========================================
  Files         131      131              
  Lines       14205    14217      +12     
  Branches       35       35              
==========================================
+ Hits        12233    12246      +13     
+ Misses       1768     1767       -1     
  Partials      204      204              

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[tataruty]

i would suggest to add some unit tests to check that deduplication works

[ciarams87]

I didn't notice the failing unit test earlier - lgtm once that's fixed 😄

[sjberman]

@tataruty Good suggestion, I did explore doing that, but the issue I found is that this is not easily reproducible. I never could figure out how the slice gets accessed in multiple places at once (it baffles me because each time this function is called should be a new entry). When running the benchmark test, out of 1000 route creations, this issue may pop up only once.