[ENH] Fix random seed in multimodal EF test (#1353)

## Description of changes

Because the multimodal embedding function test generates random images
and documents, it's possible for it to randomly get into a degenerate
state with respect to the index.

To avoid this, we fix the seed.  

## Test plan
This is the test. 
- [x] Tests pass locally with `pytest` for python, `yarn test` for js

## Documentation Changes

None

chromadb/test/ef/test_multimodal_ef.py

@@ -55,6 +55,10 @@ def test_multimodal(
     n_examples: int = 10,
     n_query_results: int = 3,
 ) -> None:
+    # Fix numpy's random seed for reproducibility
+    random_state = np.random.get_state()
+    np.random.seed(0)
+
     image_ids = [str(i) for i in range(n_examples)]
     images = [random_image() for _ in range(n_examples)]
     image_embeddings = default_ef(images)
@@ -131,6 +135,7 @@ def test_multimodal(
     )
 
     assert query_result["ids"][0] == nearest_document_neighbor_ids
+    np.random.set_state(random_state)
 
 
 @pytest.mark.xfail