Broken extended_metrics attribute

[matteomrz]

Describe the bug
When trying to access COCOEval_faster.extended_metrics I get the following Error:
TypeError: only 0-dimensional arrays can be converted to Python scalars
the error occurs in: faster_coco_eval/core/faster_eval_api.py:238

To Reproduce

1. Create any COCOEval_faster
2. Run evaluate(), accumulate() and summarize()
3. Try accessing COCOEval_faster.extended_metrics

Expected behavior
The extended metrics should be displayed without any Errors

Additional context
To fix this you should consider replacing the int cast with a call to the item() function.
faster_coco_eval version: 1.7.0
numpy version: 2.4.0

[MiXaiLL76]

faster-coco-eval 1.7.1 released