Mark some optimizer update arguments as Noneable (they were being called with Nones)

Author: akx

bitsandbytes/functional.py

@@ -1618,18 +1618,18 @@ def optimizer_update_8bit(
     g: Tensor,
     p: Tensor,
     state1: Tensor,
-    state2: Tensor,
+    state2: Optional[torch.Tensor],
     beta1: float,
     beta2: float,
     eps: float,
     step: int,
     lr: float,
     qmap1: Tensor,
-    qmap2: Tensor,
+    qmap2: Optional[torch.Tensor],
     max1: Tensor,
-    max2: Tensor,
+    max2: Optional[torch.Tensor],
     new_max1: Tensor,
-    new_max2: Tensor,
+    new_max2: Optional[torch.Tensor],
     weight_decay: float = 0.0,
     gnorm_scale: float = 1.0,
     unorm_vec: Optional[torch.Tensor] = None,
@@ -1751,16 +1751,16 @@ def optimizer_update_8bit_blockwise(
     g: Tensor,
     p: Tensor,
     state1: Tensor,
-    state2: Tensor,
+    state2: Optional[torch.Tensor],
     beta1: float,
     beta2: float,
     eps: float,
     step: int,
     lr: float,
     qmap1: Tensor,
-    qmap2: Tensor,
+    qmap2: Optional[torch.Tensor],
     absmax1: Tensor,
-    absmax2: Tensor,
+    absmax2: Optional[torch.Tensor],
     weight_decay: float = 0.0,
     gnorm_scale: float = 1.0,
     skip_zeros=False,