BREAKING CHANGE: the `zsh_reload` plugin is deprecated. Instead of using its `src`
function, use `omz reload` or `exec zsh` to reload zsh after making changes to
your `.zshrc` file.
Closes#9078
`source ~/.zshrc` is a bad practice, it doesn't make sure that the full
zsh session is reloaded and it may have side effects.
Use `$SHELL` as the path to zsh if it exists (this will fix edge cases
where the zsh used is not the first on $PATH). Otherwise, use `zsh`.