Whenever a package is installed automatically by
apt-get because it’s a dependency of some other package,
apt-get notes that fact; then if it notices that nothing depends on such a package any more, it will suggest that the package be removed. This is particularly useful for libraries.
That’s all that’s meant by “no longer required”:
apt-get doesn’t know whether you’re using the packages or not, but it knows that they were installed automatically and nothing depends on them any more.
apt-get that a package shouldn’t be considered as automatically installed, run
apt-mark and mark it as manual[ly installed]:
apt-mark manual git rsync
Or install it explicitly (this won’t do anything if the latest version of the package is already installed, except mark it as manually installed):
apt-get install git rsync
Since these packages are already installed,
apt-get won’t install them again, but it will mark them as explicitly installed and won’t suggest their removal. (If the packages aren’t the newest versions available,
apt-get will upgrade them.)