Add Python 3.13 support by removing construct version constraint

[faratech]

Problem

pdbparse failed to install on Python 3.13 due to a version constraint issue:

error: subprocess-exited-with-error
ModuleNotFoundError: No module named 'imp'

The imp module was removed in Python 3.12+, and the constraint construct<2.10 prevented installation of newer construct versions that handle this properly.

Solution

• Removed upper bound constraint on construct dependency (construct<2.10 → construct>=2.9)
• Added explicit Python version classifiers including 3.13
• Added python_requires for better dependency resolution

Testing

• ✅ Successfully installs on Python 3.13
• ✅ All functionality working (parsing, symbol extraction, etc.)
• ✅ Compatible with construct 2.10.70
• ✅ No breaking changes for older Python versions

Files Changed

• setup.py: Updated dependency constraints and Python version classifiers
• .gitignore: Added build artifacts to ignore list

Verification

import pdbparse
pdb = pdbparse.parse('example.pdb', fast_load=True)
print(f"Success: {len(pdb.streams)} streams parsed")

This fix enables pdbparse to work with modern Python versions while maintaining backward compatibility.

[vitalych]

Works for s2e as well, would be great to merge.

[vineelkovvuri]

@moyix Gentle ping can this be merged!

[v-p-b]

ICYMI I created this fork for one of my projects to depend on: https://github.com/v-p-b/pdbparse