Restore compatibility with numpy < 2

Author: FrancescAlted

src/blosc2/ctable.py

@@ -2027,7 +2027,7 @@ def _build_lex_keys(
             if not asc:
                 if raw.dtype.kind in "US":
                     # strings can't be negated — invert via rank
-                    rank = np.argsort(np.argsort(raw, stable=True), stable=True)
+                    rank = np.argsort(np.argsort(raw, kind="stable"), kind="stable")
                     lex_keys.append((n - 1 - rank).astype(np.intp))
                 elif np.issubdtype(raw.dtype, np.unsignedinteger):
                     lex_keys.append(-raw.astype(np.int64))

src/blosc2/lazyexpr.py

@@ -2759,7 +2759,7 @@ def chunked_eval(  # noqa: C901
                 unit_steps = np.all([s.step == 1 for s in item.raw if isinstance(s, slice)])
                 # shape of slice, if non-unit steps have to decompress full array into memory
                 shape_operands = item.newshape(shape) if unit_steps else shape
-                _dtype = kwargs.get("dtype", np.float64)
+                _dtype = np.dtype(kwargs.get("dtype", np.float64))
                 size_operands = math.prod(shape_operands) * len(operands) * _dtype.itemsize
                 # Only take the fast path if the size of operands is relatively small
                 if size_operands < blosc2.MAX_FAST_PATH_SIZE: