community[patch]: Invoke callback prior to yielding token fix [DeepInfra] (#20427)

- [x] **PR title**: community[patch]: Invoke callback prior to yielding
token fix for [DeepInfra]


- [x] **PR message**: 
- **Description:** Invoke callback prior to yielding token in stream
method in [DeepInfra]
    - **Issue:** https://github.com/langchain-ai/langchain/issues/16913
    - **Dependencies:** None
    - **Twitter handle:** @bolun_zhang

If no one reviews your PR within a few days, please @-mention one of
baskaryan, efriis, eyurtsev, hwchase17.

libs/community/langchain_community/llms/deepinfra.py

@@ -155,9 +155,9 @@ class DeepInfra(LLM):
         for line in _parse_stream(response.iter_lines()):
             chunk = _handle_sse_line(line)
             if chunk:
-                yield chunk
                 if run_manager:
                     run_manager.on_llm_new_token(chunk.text)
+                yield chunk
 
     async def _astream(
         self,
@@ -174,9 +174,9 @@ class DeepInfra(LLM):
             async for line in _parse_stream_async(response.content):
                 chunk = _handle_sse_line(line)
                 if chunk:
-                    yield chunk
                     if run_manager:
                         await run_manager.on_llm_new_token(chunk.text)
+                    yield chunk
 
 
 def _parse_stream(rbody: Iterator[bytes]) -> Iterator[str]: