MInor fix to await for clain before request it

When requesting to add a claim for the first time, it's possible that it may not be ready yet. Waiting for it will prevent errors. Additionally, Firebase might return a cached `idToken`, which can be forced using `(true)` as a parameter.

content/learn/developer/todo-app-tutorial/todo-firebase-jwt.md

@@ -179,8 +179,8 @@ export const AuthProvider = ({ children }) => {
       setLoading(false)
       setCurrentUser(user)
       if (user) {
-        addUserClaim({email: user.email})
-        const token = await user.getIdToken(); 
+        await addUserClaim({email: user.email})
+        const token = await user.getIdToken(true); 
         setIdToken(token);
       }
     });