feat(memory): optimize collection preallocation where capacity is known

[fvaleye]

Description

Following this, this work implements a first round of preallocating collections when their size is known, to avoid unnecessary reallocations. This applies to Vec, HashMap (with_capacity), and other dynamically sized collections.
Preallocating memory improves efficiency and reduces overhead when the final size is known.

[codecov]

Codecov Report

❌ Patch coverage is 86.95652% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.73%. Comparing base (4106d43) to head (580a0e8).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/core/src/writer/json.rs	0.00%	2 Missing ⚠️
python/src/filesystem.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3895      +/-   ##
==========================================
- Coverage   73.74%   73.73%   -0.02%     
==========================================
  Files         151      151              
  Lines       39371    39352      -19     
  Branches    39371    39352      -19     
==========================================
- Hits        29036    29018      -18     
  Misses       9023     9023              
+ Partials     1312     1311       -1     

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[roeap]

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