fix: clarify max_age can be None

Author: jorwoods

tableauserverclient/server/request_options.py

@@ -316,10 +316,11 @@ class Workbook:
 
 
 class _DataExportOptions(RequestOptionsBase):
-    def __init__(self, maxage: int = -1):
+    def __init__(self, maxage: int | None = -1):
         super().__init__()
         self.view_filters: list[tuple[str, str]] = []
         self.view_parameters: list[tuple[str, str]] = []
+        self._max_age: int | None = None
         self.max_age: int | None = maxage
         """
         This setting will affect the contents of the workbook as they are exported.
@@ -329,12 +330,12 @@ def __init__(self, maxage: int = -1):
         self.language: str | None = None
 
     @property
-    def max_age(self) -> int:
+    def max_age(self) -> int | None:
         return self._max_age
 
     @max_age.setter
-    @property_is_int(range=(0, 240), allowed=[-1])
-    def max_age(self, value):
+    @property_is_int(range=(0, 240), allowed=[-1, None])
+    def max_age(self, value: int | None) -> None:
         self._max_age = value
 
     def get_query_params(self):