[Bug fix] Fix vertex ai integration issue (#1257)

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "embedchain"
-version = "0.1.78"
+version = "0.1.79"
 description = "Simplest open source retrieval(RAG) framework"
 authors = [
     "Taranjeet Singh <taranjeet@embedchain.ai>",
@@ -152,6 +152,7 @@ google-api-core = { version = "^2.15.0", optional = true }
 boto3 = { version = "^1.34.20", optional = true }
 langchain-mistralai = { version = "^0.0.3", optional = true }
 langchain-openai = "^0.0.5"
+langchain-google-vertexai = { version = "^0.0.5", optional = true }
 
 [tool.poetry.group.dev.dependencies]
 black = "^23.3.0"
@@ -191,7 +192,7 @@ dataloaders=[
     "sentence-transformers",
     "unstructured",
 ]
-vertexai = ["google-cloud-aiplatform"]
+vertexai = ["langchain-google-vertexai"]
 llama2 = ["replicate"]
 gmail = [
     "requests",