Remove duplicate text about 'handling user data' in the security doc

[dtrzhetsynskyi]

In the block about handling user data, there is a duplicate paragraph: "User information should be treated as a central piece of data accessible throughout the application. If you are already using react-query, consider using it for storing user data as well. Alternatively, you can leverage React context with hooks or opt for a third-party state management library to efficiently manage user state across your application."

This paragraph is a duplicate to the text above it which seems to be newer: "User info should be considered a global piece of state which should be available from anywhere in the application. If you are already using react-query, you can use react-query-auth library for handling user state which will handle all the things for you after you provide it some configuration. Otherwise, you can use react context + hooks, or some 3rd party state management library."