Add collision detection for hook env directories

[kenwoodjw]

Closed #325

[codecov]

Codecov Report

❌ Patch coverage is 76.19048% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.10%. Comparing base (054e1fb) to head (a99db78).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
src/languages/docker.rs	0.00%	1 Missing ⚠️
src/languages/golang/golang.rs	0.00%	1 Missing ⚠️
src/languages/node/node.rs	0.00%	1 Missing ⚠️
src/languages/pygrep/pygrep.rs	0.00%	1 Missing ⚠️
src/languages/python/python.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #914      +/-   ##
==========================================
+ Coverage   89.98%   90.10%   +0.11%     
==========================================
  Files          63       64       +1     
  Lines       11756    11944     +188     
==========================================
+ Hits        10579    10762     +183     
- Misses       1177     1182       +5     

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[j178]

Thanks for working on this! I switched to using tempfile for more reliable detection and to create the directory safely. This helps avoid TOCTOU issues.