Add Provides-Dist metadata for onnxruntime variant packages
- Created custom Distribution class that adds Provides-Dist metadata
- All variant packages (onnxruntime-gpu, onnxruntime-openvino, etc.) now declare they provide onnxruntime
- This fixes dependency resolution issues where both onnxruntime and onnxruntime-gpu could be installed
- Addresses issue #26807
Co-authored-by: fs-eire <7679871+fs-eire@users.noreply.github.com>
