chore: Migrate from Preview to Stable Package for Vertex AI Integration

integrations/google_vertex/src/haystack_integrations/components/generators/google_vertex/chat/gemini.py

@@ -8,7 +8,7 @@
 from haystack.dataclasses.chat_message import ChatMessage, ChatRole
 from haystack.utils import deserialize_callable, serialize_callable
 from vertexai import init as vertexai_init
-from vertexai.preview.generative_models import (
+from vertexai.generative_models import (
     Content,
     GenerationConfig,
     GenerationResponse,

integrations/google_vertex/src/haystack_integrations/components/generators/google_vertex/gemini.py

@@ -134,6 +134,7 @@ def to_dict(self) -> Dict[str, Any]:
             tools=self._tools,
             streaming_callback=callback_name,
         )
+
         if (tools := data["init_parameters"].get("tools")) is not None:
             data["init_parameters"]["tools"] = [Tool.to_dict(t) for t in tools]
         if (generation_config := data["init_parameters"].get("generation_config")) is not None:

integrations/google_vertex/tests/test_gemini.py

@@ -1,7 +1,7 @@
 from unittest.mock import MagicMock, Mock, patch
 
 from haystack.dataclasses import StreamingChunk
-from vertexai.preview.generative_models import (
+from vertexai.generative_models import (
     FunctionDeclaration,
     GenerationConfig,
     HarmBlockThreshold,
@@ -103,6 +103,7 @@ def test_to_dict_with_params(_mock_vertexai_init, _mock_generative_model):
         safety_settings=safety_settings,
         tools=[tool],
     )
+
     assert gemini.to_dict() == {
         "type": "haystack_integrations.components.generators.google_vertex.gemini.VertexAIGeminiGenerator",
         "init_parameters": {