community[patch]: update Gradient embeddings (#14846)

- **Description:** Going forward, we have a own API `pip install
gradientai`. Therefore gradually removing the self-build packages in
llamaindex, haystack and langchain.
  - **Issue:** None.
  - **Dependencies:** `pip install gradientai`
  - **Tag maintainer:** @michaelfeil

libs/langchain/langchain/embeddings/gradient_ai.py

@@ -1,6 +1,3 @@
-from langchain_community.embeddings.gradient_ai import (
-    GradientEmbeddings,
-    TinyAsyncGradientEmbeddingClient,
-)
+from langchain_community.embeddings.gradient_ai import GradientEmbeddings
 
-__all__ = ["GradientEmbeddings", "TinyAsyncGradientEmbeddingClient"]
+__all__ = ["GradientEmbeddings"]