The name of the file in my case was not the ros-archive-keyring.gpg, but ros2-latest-archive-keyring.gpg instead.
This helped in my case (Ubuntu 22.04.4 LTS + ROS2 Humble). Maybe this will be useful for someone else:
ROS2_LATEST_ARCHIVE_KEYRING="/usr/share/keyrings/ros2-latest-archive-keyring.gpg"
sudo rm -f ${ROS2_LATEST_ARCHIVE_KEYRING}
sudo curl -sSL https://raw.githubusercontent.com/ros/rosdistro/master/ros.key -o ${ROS2_LATEST_ARCHIVE_KEYRING}