Add gc.collect() function only with test-hooks feature

[davidhewitt]

Might be useful for #397 ?

[codspeed-hq]

Merging this PR will not alter performance

✅ 16 untouched benchmarks
⏩ 15 skipped benchmarks¹

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_{Comparing dh/gc-collect (efd0fec) with main (33e47c6)}

Footnotes

1. 15 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

Codecov Results 📊

✅ Patch coverage is 100.00%. Project has 23782 uncovered lines.
✅ Project coverage is 64.56%. Comparing base (base) to head (head).

Coverage diff

@@            Coverage Diff             @@
##          main       #PR       +/-##
==========================================
+ Coverage    64.56%    64.56%        —%
==========================================
  Files          258       258         —
  Lines        67096     67096         —
  Branches    143260    143260         —
==========================================
+ Hits         43314     43314         —
- Misses       23782     23782         —
- Partials      3241      3241         —

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Generated by Codecov Action

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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