add gemma3 support

[eaidova]

What does this PR do?

Fixes # #1197

Text-Only

from transformers import AutoTokenizer
from optimum.intel.openvino import OVModelForCauslaLM

model_id = "google/gemma-3-1b-it"

tokenizer = AutoTokenizer.from_pretrained(model_id)
model = OVModelForCauslaLM.from_pretrained(model_id, device_map="auto")

input_ids = tokenizer("Write me a poem about Machine Learning.", return_tensors="pt")

outputs = model.generate(**input_ids, max_new_tokens=100)
text = tokenizer.batch_decode(outputs, skip_special_tokens=True)

print(text)

Image-Text

from transformers import AutoProcessor
from optimum.intel.openvino import OVModelForVisualCuasalLM

model_id = "google/gemma-3-4b-it"
model = OVModelForVisualCuasalLM.from_pretrained(model_id)
processor = AutoProcessor.from_pretrained(model_id, padding_side="left")

url = "https://media.istockphoto.com/id/1192867753/photo/cow-in-berchida-beach-siniscola.jpg?s=612x612&w=0&k=20&c=v0hjjniwsMNfJSuKWZuIn8pssmD5h5bSN1peBd1CmH4="
messages = [
    {
        "role": "system",
        "content": [
            {"type": "text", "text": "You are a helpful assistant."}
        ]
    },
    {
        "role": "user", "content": [
            {"type": "image", "url": url},
            {"type": "text", "text": "What is shown in this image?"},
        ]
    },
]
inputs = processor.apply_chat_template(
    messages,
    tokenize=True,
    return_dict=True,
    return_tensors="pt",
    add_generation_prompt=True,
)

output = model.generate(**inputs, max_new_tokens=50)
print(processor.decode(output[0, inputs.input_ids.shape[1]: ], skip_special_tokens=True))

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

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[IlyasMoutawwakil]

shouldn't this be 4.50 since the model is only available on 4.49.0-Gemma-3 and later