fix: error occurs when trying to get str(array)

Signed-off-by: Frost Ming <[email protected]>

Author: frostming

tests/test_items.py

@@ -307,6 +307,7 @@ def test_array_behaves_like_a_list():
     content = """a = [1, 2,] # Comment
 """
     doc = parse(content)
+    assert str(doc["a"]) == "[1, 2]"
 
     assert doc["a"] == [1, 2]
     doc["a"] += [3, 4]

tomlkit/items.py

@@ -1414,9 +1414,6 @@ def __delitem__(self, key: Union[int, slice]):
 
         self._reindex()
 
-    def __str__(self):
-        return str([v.value.value for v in self._iter_items() if v.value is not None])
-
     def _getstate(self, protocol=3):
         return list(self._iter_items()), self._trivia, self._multiline