[BUG] Raise exception when attempting to change DF (#1461)

## Description of changes

*Summarize the changes made by this PR.*
 - Improvements & Bug fixes
	 - Resolves #1052 

## 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/api/models/Collection.py

@@ -380,6 +380,9 @@ def modify(
         """
         if metadata is not None:
             validate_metadata(metadata)
+            if "hnsw:space" in metadata:
+                raise ValueError(
+                    "Changing the distance function of a collection once it is created is not supported currently.")
 
         self._client._modify(id=self.id, new_name=name, new_metadata=metadata)
         if name:

chromadb/test/test_api.py

@@ -360,6 +360,13 @@ def test_modify_error_on_existing_name(api):
     with pytest.raises(Exception):
         c2.modify(name="testspace")
 
+def test_modify_warn_on_DF_change(api, caplog):
+    api.reset()
+
+    collection = api.create_collection("testspace")
+
+    with pytest.raises(Exception, match="not supported") as e:
+        collection.modify(metadata={"hnsw:space": "cosine"})
 
 def test_metadata_cru(api):
     api.reset()