test(instrumentation-mongoose): use unique collections

[Ugzuzg]

Which problem is this PR solving?

• Fix flaky tests in mongoose

Short description of the changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.44%. Comparing base (02e48b9) to head (03a01ab).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3022   +/-   ##
=======================================
  Coverage   91.44%   91.44%           
=======================================
  Files         146      146           
  Lines        8192     8192           
  Branches     1846     1846           
=======================================
  Hits         7491     7491           
  Misses        701      701           

Flag	Coverage Δ
instrumentation-mongoose	90.74% <ø> (ø)

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[trentm]

Thanks!