Make access_token optional in the case that OAuth is used.

Author: Bre77

tesla_fleet_api/teslemetry/teslemetry.py

@@ -14,12 +14,17 @@ class Teslemetry(TeslaFleetApi):
     def __init__(
         self,
         session: aiohttp.ClientSession,
-        access_token: str,
+        access_token: str = "",
         server: str = "https://api.teslemetry.com",
         refresh_hook: Callable[[], Awaitable[str | None]] | None = None,
     ):
         """Initialize the Teslemetry API."""
 
+        if not access_token and not refresh_hook:
+            raise ValueError(
+                "access_token or refresh_hook are required to authenticate"
+            )
+
         self.session = session
         self.access_token = access_token
         self.server = server