Fixup use default_rng for cpython code.

sgkit/stats/genedrop.py

@@ -257,16 +257,16 @@ def simulate_genedrop(
 
     Simulation with random seed
 
-    >>> sim = sg.simulate_genedrop(ds, merge=False, seed=0)
+    >>> sim = sg.simulate_genedrop(ds, merge=False, seed=1)
     >>> sim["sample_id"] = ds["sample_id"]
     >>> sim["variant_position"] = ds["variant_position"]
     >>> sim["variant_allele"] = ds["variant_allele"]
     >>> sg.display_genotypes(sim) # doctest: +NORMALIZE_WHITESPACE
     samples    S0   S1   S2   S3   S4
     variants
-    0         0/1  2/3  1/2  1/3  1/1
-    1         0/1  2/3  0/3  0/2  3/2
-    2         0/1  2/3  1/3  1/3  3/3
+    0         0/1  2/3  0/3  1/3  0/3
+    1         0/1  2/3  0/3  0/3  0/3
+    2         0/1  2/3  0/2  0/3  2/0
 
     Simulation with seed per variant (including duplicates)
 
@@ -302,10 +302,11 @@ def simulate_genedrop(
     gt = da.asarray(ds[call_genotype].data)
     parent = da.asarray(ds[parent].data, chunks=ds[parent].shape)
     if hasattr(seed, "__len__"):
-        seeds = da.array(seed)
+        seeds = np.array(seed, copy=False)
+    elif seed is not None:
+        rng = np.random.default_rng(seed)
+        seeds = rng.integers(2**32, size=len(gt), dtype=np.uint32)
     else:
-        if seed is not None:
-            np.random.seed(seed)
         seeds = np.random.randint(2**32, size=len(gt), dtype=np.uint32)
     seeds = da.asarray(seeds, chunks=gt.chunks[0])
     if method == EST_DIPLOID: