Reduced copying in _from_sparse method [skip ci]

Author: ankane

pgvector/sparsevec.py

@@ -100,7 +100,7 @@ def _from_dict(self, d: dict[int, float], dim: int) -> None:
         self._values = [float(v[1]) for v in elements]
 
     def _from_sparse(self, arr: sparray | spmatrix) -> None:
-        value: coo_array | coo_matrix = arr.tocoo()  # type: ignore
+        value: coo_array | coo_matrix = arr.tocoo(copy=False)  # type: ignore
 
         shape = cast(tuple[int], value.shape)
         if len(shape) == 1: