Fix atleast_{1,2,3}d() with no arguments description (pytorch#156042)

Fixes pytorch#130667

## Test Result

### Before
![image](https://github.com/user-attachments/assets/7e3a6764-872a-4573-8bec-e7219f920a15)
![image](https://github.com/user-attachments/assets/194be00c-9a29-44cf-b6bc-4d261a12d04e)
![image](https://github.com/user-attachments/assets/21cd6a4f-0793-44e3-9073-7b8b801f997c)

### After

![image](https://github.com/user-attachments/assets/fdbaa2ff-f13c-4fa9-bf52-0810faa698bd)
![image](https://github.com/user-attachments/assets/0374b474-4c6b-4b7d-abea-70e3df0c0a06)
![image](https://github.com/user-attachments/assets/9f9dc188-60e2-4c0f-9e23-36a39310008c)

Pull Request resolved: pytorch#156042
Approved by: https://github.com/zou3519

Author: zeshengzong

torch/functional.py

@@ -1522,7 +1522,7 @@ def atleast_1d(*tensors):
     Input tensors with one or more dimensions are returned as-is.
 
     Args:
-        input (Tensor or list of Tensors)
+        input (Tensor or sequence of Tensors): tensor(s) to be converted to at least 1-dimensional.
 
     Returns:
         output (Tensor or tuple of Tensors)
@@ -1543,6 +1543,8 @@ def atleast_1d(*tensors):
         >>> y = torch.tensor(1.)
         >>> torch.atleast_1d((x, y))
         (tensor([0.5000]), tensor([1.]))
+        >>> torch.atleast_1d()
+        ()
     """
     # This wrapper exists to support variadic args.
     if has_torch_function(tensors):
@@ -1558,7 +1560,7 @@ def atleast_2d(*tensors):
     Input tensors with two or more dimensions are returned as-is.
 
     Args:
-        input (Tensor or list of Tensors)
+        input (Tensor or sequence of Tensors): tensor(s) to be converted to at least 2-dimensional.
 
     Returns:
         output (Tensor or tuple of Tensors)
@@ -1581,6 +1583,8 @@ def atleast_2d(*tensors):
         >>> y = torch.tensor(1.)
         >>> torch.atleast_2d((x, y))
         (tensor([[0.5000]]), tensor([[1.]]))
+        >>> torch.atleast_2d()
+        ()
     """
     # This wrapper exists to support variadic args.
     if has_torch_function(tensors):
@@ -1596,7 +1600,7 @@ def atleast_3d(*tensors):
     Input tensors with three or more dimensions are returned as-is.
 
     Args:
-        input (Tensor or list of Tensors)
+        input (Tensor or sequence of Tensors): tensor(s) to be converted to at least 3-dimensional.
 
     Returns:
         output (Tensor or tuple of Tensors)
@@ -1627,6 +1631,8 @@ def atleast_3d(*tensors):
         >>> y = torch.tensor(1.0)
         >>> torch.atleast_3d((x, y))
         (tensor([[[0.5000]]]), tensor([[[1.]]]))
+        >>> torch.atleast_3d()
+        ()
     """
     # This wrapper exists to support variadic args.
     if has_torch_function(tensors):