This is some relic from former configurations, and might have been wrong quite
some time now. However, in Emacs 27+, package initialization is done before
loading user-init-file, and thus we don't have to do it by hand. Before that,
package initialization was done after reading user-init-file, but before calling
after-init-hook, and since we needed to load some packages in the init file, we
had to initialize package.el ourselves.