fix: update torch frontnend Tensor method cumprod's arg defaults to m…

…atch with native torch

ivy/functional/frontends/torch/tensor.py

@@ -1391,7 +1391,7 @@ def item(self):
 
     @numpy_to_torch_style_args
     @with_unsupported_dtypes({"2.1.2 and below": ("float16",)}, "torch")
-    def cumprod(self, dim, dtype):
+    def cumprod(self, dim, dtype=None):
         return torch_frontend.cumprod(self, dim, dtype=dtype)
 
     @numpy_to_torch_style_args