fix(vertex): also refresh auth if there is no token

Author: RobertCraigie

src/anthropic/lib/vertex/_client.py

@@ -164,7 +164,7 @@ def _ensure_access_token(self) -> str:
             if not self.project_id:
                 self.project_id = project_id
 
-        if self.credentials.expired:
+        if self.credentials.expired or not self.credentials.token:
             refresh_auth(self.credentials)
 
         if not self.credentials.token:
@@ -330,7 +330,7 @@ async def _ensure_access_token(self) -> str:
             if not self.project_id:
                 self.project_id = project_id
 
-        if self.credentials.expired:
+        if self.credentials.expired or not self.credentials.token:
             await asyncify(refresh_auth)(self.credentials)
 
         if not self.credentials.token: