In case of netstandard 2.0, improved ArrayPool usage.

Instead of manually clearing the rented array before returning it back to the pool, added clearArray: true argument for the Return() call.

Author: Seramis

src/ByteAether.Ulid/Ulid.New.cs

@@ -167,8 +167,7 @@ private static void FillRandom(Span<byte> bytes, bool isMonotonic)
 			_rng.GetBytes(random, 0, _ulidSizeRandom);
 			new ReadOnlySpan<byte>(random, 0, _ulidSizeRandom).CopyTo(bytes[_ulidSizeTime..]);
 
-			Array.Clear(random, 0, _ulidSizeRandom);
-			ArrayPool<byte>.Shared.Return(random);
+			ArrayPool<byte>.Shared.Return(random, true);
 #endif
 			return;
 		}