feat: expose package version from metadata

[haosenwang1018]

Summary

• add __version__ in colpali_engine.__init__
• resolve the version using importlib.metadata.version("colpali_engine")
• add a safe fallback (0.0.0) when metadata is unavailable

Why

This provides a stable, standard way to introspect the installed package version at runtime.

Testing

• additive change only
• import surface remains backward-compatible

[ManuelFay]

I made a few comments. Overall, not too sure on what's the standard way to do expose the version, @pdesgarets happy to have your input

[ManuelFay]

A few things:

1. I would assume you need the pypy distribution name right ? so colpali-engine and not colpali_engine

2. the other imports surely need to be under, it feels like there could be some dangerous behavior in the future if any model files use some branching based on versions.

Proposed fix:

from importlib.metadata import PackageNotFoundError, version

try:
    __version__ = version("colpali-engine")
except PackageNotFoundError:
    __version__ = "0.0.0"

from .models import * 

[ManuelFay]

@haosenwang1018 what is the point here ? Since you can check the package version yourself based on the code you propose ?

Any point to having this be directly integrated ?