Add Python object reference tracking

[pablogsal]

This feature adds the capability to track Python objects throughout
their lifecycle in memray. The implementation introduces a reference
tracking system that records PyObject creation and destruction events,
storing them as TrackedObject records in the memray capture file with
associated stack traces. The Tracker class now accepts a
reference_tracking flag to enable this functionality and provides a
get_surviving_objects() method to retrieve live objects at the end of
tracking.

Object tracking works across threads and supports native, Python, and
hybrid stack traces, providing insights into Python object
lifetimes. This enhancement extends memray beyond memory allocation
tracking to give developers a powerful tool for understanding object
lifecycles and identifying potential reference leaks.

With this addition, memray can now correlate memory allocations with the
Python objects that trigger them, enabling more precise debugging of
memory usage patterns. The feature is particularly useful for
identifying objects that persist longer than expected or detecting
unexpected object creation patterns. By tracking both memory allocations
and object references, memray provides a more complete picture of a
program's memory behavior, helping developers optimize memory usage and
resolve leaks more effectively.

This implementation leverages the new Python reference tracing API that
was introduced in CPython 3.13.

Signed-off-by: Pablo Galindo pablogsal@gmail.com

Issue number of the reported bug or feature request: #

Describe your changes
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Testing performed
Describe the testing you have performed to ensure that the bug has been addressed, or that the new feature works as planned.

Additional context
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[codecov-commenter]

Codecov Report

Attention: Patch coverage is 19.15423% with 325 lines in your changes missing coverage. Please review.

Project coverage is 90.46%. Comparing base (864fc2d) to head (a03e9de).

Files with missing lines	Patch %	Lines
tests/integration/test_object_tracking.py	28.76%	161 Missing ⚠️
src/memray/_memray/record_reader.cpp	0.00%	62 Missing ⚠️
src/memray/_memray/tracking_api.cpp	21.42%	44 Missing ⚠️
src/memray/_memray/records.cpp	0.00%	23 Missing ⚠️
src/memray/_memray/record_writer.cpp	0.00%	15 Missing ⚠️
src/memray/_memray/tracking_api.h	0.00%	13 Missing ⚠️
src/memray/_memray/socket_reader_thread.cpp	0.00%	3 Missing ⚠️
src/memray/_memray/compat.h	0.00%	2 Missing ⚠️
src/memray/_memray/hooks.cpp	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #752      +/-   ##
==========================================
- Coverage   92.97%   90.46%   -2.52%     
==========================================
  Files          95       96       +1     
  Lines       11687    12086     +399     
  Branches      407      421      +14     
==========================================
+ Hits        10866    10933      +67     
- Misses        821     1153     +332     

Flag	Coverage Δ
cpp	90.46% <19.15%> (-2.52%)	⬇️
python_and_cython	90.46% <19.15%> (-2.52%)	⬇️

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[pablogsal]

Tests require 3.13.3 at least because before there is a bug that causes some objects to be identified wrongly. cibuildwheel only has this when pypa/cibuildwheel#2359 passes

[joerick]

I just released cibuildwheel with 3.13.3 support!