community[patch]: fix public interface for embeddings module (#21650)

## Description

The existing public interface for `langchain_community.emeddings` is
broken. In this file, `__all__` is statically defined, but is
subsequently overwritten with a dynamic expression, which type checkers
like pyright do not support. pyright actually gives the following
diagnostic on the line I am requesting we remove:


[reportUnsupportedDunderAll](https://github.com/microsoft/pyright/blob/main/docs/configuration.md#reportUnsupportedDunderAll):

```
Operation on "__all__" is not supported, so exported symbol list may be incorrect
```

Currently, I get the following errors when attempting to use publicablly
exported classes in `langchain_community.emeddings`:

```python
import langchain_community.embeddings

langchain_community.embeddings.HuggingFaceEmbeddings(...)  #  error: "HuggingFaceEmbeddings" is not exported from module "langchain_community.embeddings" (reportPrivateImportUsage)
```

This is solved easily by removing the dynamic expression.

libs/community/langchain_community/embeddings/titan_takeoff.py

@@ -1,5 +1,5 @@
 from enum import Enum
-from typing import Any, List, Optional, Set, Union
+from typing import Any, Dict, List, Optional, Set, Union
 
 from langchain_core.embeddings import Embeddings
 from langchain_core.pydantic_v1 import BaseModel
@@ -142,11 +142,12 @@ class TitanTakeoffEmbed(Embeddings):
 
     def _embed(
         self, input: Union[List[str], str], consumer_group: Optional[str]
-    ) -> dict:
+    ) -> Dict[str, Any]:
         """Embed text.
 
         Args:
-            input (List[str]): prompt/document or list of prompts/documents to embed
+            input (Union[List[str], str]): prompt/document or list of prompts/documents
+            to embed
             consumer_group (Optional[str]): what consumer group to send the embedding
             request to. If not specified and there is only one
             consumer group specified during initialization, it will be used. If there