Write a function `remove_nested` that takes a tuple as input and returns a new tuple with all nested tuples removed. The function should iterate through the elements of the input tuple and include only those elements that are not tuples themselves.
#### Example Usage
```python [main.nopy]
print(remove_nested((1, 5, 7, (4, 6), 10))) # Output: (1, 5, 7, 10)
print(remove_nested((2, 6, 8, (5, 7), 11))) # Output: (2, 6, 8, 11)
print(remove_nested((3, 7, 9, (6, 8), 12))) # Output: (3, 7, 9, 12)
print(remove_nested((3, 7, 9, (6, 8), (5, 12), 12))) # Output: (3, 7, 9, 12)
```
#### Constraints
- The input will always be a tuple.
- The elements of the tuple can be of any type.
- Nested tuples can appear at any position in the input tuple.