[CLN] Import json at top-level in embedding_functions (chroma-core#1562)

## Description of changes

*Summarize the changes made by this PR.*
 - Improvements & Bug fixes
	 - Move `import json` out of Amazon Bedrock EF and to top-level imports

## Test plan
*How are these changes tested?*

- [x] Tests pass locally with `pytest` for python, `yarn test` for js

## Documentation Changes
*Are all docstrings for user-facing APIs updated if required? Do we need
to make documentation changes in the [docs
repository](https://github.com/chroma-core/docs)?*

chromadb/utils/embedding_functions.py

@@ -23,6 +23,7 @@
 import numpy.typing as npt
 import importlib
 import inspect
+import json
 import sys
 from typing import Optional
 
@@ -740,8 +741,6 @@ def __init__(
         )
 
     def __call__(self, input: Documents) -> Embeddings:
-        import json
-
         accept = "application/json"
         content_type = "application/json"
         embeddings = []