use dot instead of tilde on download url (#5682)

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It appears that when saving artifacts with tilde to github releases, the tilde gets converted to a dot most likely due to url restrictions.

Author: claraberendsen

source/Installation/_Apt-Repositories.rst

@@ -16,5 +16,5 @@ Updates to repository configuration will occur automatically when new versions o
 
    $ sudo apt update && sudo apt install curl -y
    $ export ROS_APT_SOURCE_VERSION=$(curl -s https://api.github.com/repos/ros-infrastructure/ros-apt-source/releases/latest | grep -F "tag_name" | awk -F\" '{print $4}')
-   $ curl -o /tmp/ros2-apt-source.deb "https://github.com/ros-infrastructure/ros-apt-source/releases/download/${ROS_APT_SOURCE_VERSION}/ros2-apt-source_${ROS_APT_SOURCE_VERSION}~$(. /etc/os-release && echo $VERSION_CODENAME)_all.deb" # If using Ubuntu derivates use $UBUNTU_CODENAME
+   $ curl -o /tmp/ros2-apt-source.deb "https://github.com/ros-infrastructure/ros-apt-source/releases/download/${ROS_APT_SOURCE_VERSION}/ros2-apt-source_${ROS_APT_SOURCE_VERSION}.$(. /etc/os-release && echo $VERSION_CODENAME)_all.deb" # If using Ubuntu derivates use $UBUNTU_CODENAME
    $ sudo apt install /tmp/ros2-apt-source.deb