[Bugfix] Fix missing int type for -n in multi-image example

[Isotr0py]

• Fix missing type=int for -n in vision_language_multi_image.py:

vision_language_multi_image.py: error: argument --num-images/-n: invalid choice: '3' (choose from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)

[github-actions]

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