Incorrect use of "dnf update" in puppetize.sh

To puppetize a Fedora env, the cmd "dnf -y update" is not correct used.

First "update" is a deprecated cmd to upgrade packages, check here

Second, from other OS's similiar cmds in puppetize.sh, the purpose here is to "synchronize the package index files from their sources". For this purpose the cmd should be "dnf check-update"