fix serializer from_array v2 to v3

Author: brokkoli71

src/zarr/core/array.py

@@ -3992,7 +3992,7 @@ async def from_array(
             else:
                 compressors = "auto"
         if serializer == "keep":
-            if zarr_format == 3:
+            if zarr_format == 3 and data.metadata.zarr_format == 3:
                 serializer = cast(SerializerLike, data.serializer)
             else:
                 serializer = "auto"

tests/test_array.py

@@ -1365,6 +1365,7 @@ async def test_creation_from_other_zarr_format(
     assert result.fill_value == src.fill_value
     assert result.dtype == src.dtype
     assert result.chunks == src.chunks
+    assert result.metadata.zarr_format == new_format
     if src_format == new_format:
         assert result.metadata == src.metadata