Add a numeric check to the PaliGemma2 conversion script

[james77777778]

Fix #2005
This PR adds a numeric check to the PaliGemma2 conversion script.

I noticed that the outputs are a bit weird when running on the CPU (Ryzen 7700). However, they work fine on the GPU (RTX 4070).

Here are the results (prompt: "describe en\n"):

Variant		big_vision	KerasHub
"pali_gemma2_3b_pt_448"	cpu	"A brown dairy"	"A brown dairy cow on the beach"	🔶
"pali_gemma2_3b_pt_448"	gpu	"A cow on the beach"	"A cow on the beach"	✅
"pali_gemma2_3b_ft_docci_448"	cpu	"A brown cow is standing on the shore of the shore of the shore of the shore of the shore of the shore. The sun is casting a shade over the"	"A brown cow is standing on the shore of the shore of the shore of the shore of the shore of the shore of the shore. The"	🔶
"pali_gemma2_3b_ft_docci_448"	gpu	"A cow on a beach. The cow is brown with a white spot on its head and a white tag on its ear. The cow is"	"A cow on a beach. The cow is brown with a white spot on its head and a white tag on its ear. The cow is"	✅

• ✅: matched
• 🔶: partially matched

cc @divyashreepathihalli

[mattdangerw]

Thanks; look good! Kinda awkward the big_vision is so difficult to install, but we can go with this for now.

We could consider a safetensors converter and validator for this at some point. Not that transformers is a better source of comparison than big_vision. But more easily installable and would fit with other builtin converters we have.