getFollowingUsers = async (req, res) => {
  try {
    const relationships = await Relationship.find({
      follower: req.userId,
    })
      .populate("following", "_id name avatar location")
      .lean();

    const followingUsers = relationships
      .map((relationship) => ({
        ...relationship.following,
        followingSince: relationship.createdAt,
      }))
      .sort((a, b) => b.followingSince - a.followingSince);

    res.status(200).json(followingUsers);
  } catch (error) {
    res.status(500).json({
      message: "Some error occurred while retrieving the following users",
    });
  }
}
Retrieves the users that the current user is following, including their name, avatar, location,
and the date when they were followed, sorted by the most recent follow date.

@route GET /users/following

@param {string} req.userId - The ID of the current user.