fix: store PathBuf with weak pointers to handle cache clearing

[Boshen]

fixes of #872

The solution is not optimal, I spent the whole day trying to understand synchronization but couldn't figure it out, so resorting to this really bad implementation.

The good news is that I came up with a simple failing test for future improvements.

[graphite-app]

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[codspeed-hq]

CodSpeed Performance Report

Merging #879 will degrade performances by 4.77%

_{Comparing clear_cache (2492bd2) with main (9b82017)¹}

Summary

⚡ 1 improvement
❌ 1 regression
✅ 10 untouched
⏩ 5 skipped²

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	small	11.6 µs	11.2 µs	+4%
❌	resolver_real[multi-thread]	469.6 µs	493.1 µs	-4.77%

Footnotes

1. No successful run was found on main (2492bd2) during the generation of this report, so 9b82017 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

2. 5 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. ↩

[codecov]

Codecov Report

❌ Patch coverage is 94.87179% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 94.39%. Comparing base (6887252) to head (2492bd2).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/cache/cache_impl.rs	87.50%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #879      +/-   ##
==========================================
+ Coverage   94.36%   94.39%   +0.02%     
==========================================
  Files          17       17              
  Lines        3230     3247      +17     
==========================================
+ Hits         3048     3065      +17     
  Misses        182      182              

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[Boshen]

Merge activity

• Nov 27, 3:09 PM UTC: The merge label 'merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Nov 27, 3:09 PM UTC: Boshen added this pull request to the Graphite merge queue.
• Nov 27, 3:13 PM UTC: Merged by the Graphite merge queue.