Write a function that takes a list of strings and returns a new list where any consecutive duplicate elements are collapsed to a single occurrence. Only duplicates that are adjacent should be removed; if the same value appears later non-consecutively it should be kept. Examples: - ['a', 'a', 'b', 'b', 'a'] -> ['a', 'b', 'a'] - ['hello', 'hello', 'world'] -> ['hello', 'world'] Implement the function solve(items: list[str]) -> list[str].
(['a', 'a', 'b', 'b', 'a'])['a', 'b', 'a']