refactor(fedora)!: remove deprecated `fedora` plugin

BREAKING CHANGE: the `fedora` plugin has been removed. Use the `dnf` plugin instead.

plugins/fedora/README.md

-The fedora plugin is deprecated. Use the [dnf plugin](https://github.com/ohmyzsh/ohmyzsh/tree/master/plugins/dnf) instead.

plugins/fedora/fedora.plugin.zsh

-print -P "%F{yellow}The 'fedora' plugin is deprecated. Use the '%Udnf%u' plugin instead.%f"
-
-source "$ZSH/plugins/dnf/dnf.plugin.zsh"