Remove Duplicates from Sorted List

Given the `head` of a sorted linked list, _delete all duplicates such that each element appears only once_. Return _the linked list **sorted** as well_.   **Example 1:** **Input:** head = [1,1,2] **Output:** [1,2] ``` **Example 2:** **Input:** head = [1,1,2,3,3] **Output:** [1,2,3] ```   **Constraints:** - The number of nodes in the list is in the range `[0, 300]`. - `-100 <= Node.val <= 100` - The list is guaranteed to be **sorted** in ascending order.