Remove zsh plugin manager

Plugins are managed directly through pacman packages now. Since I am
only using six zsh plugins and they are staying relatively constant and
not changing much, pacman seems a much more sane way to manage them
without cluttering up my zsh initialization routine. All zgen management
can go and just needs 6 `source` lines in order to load the plugin
entrypoints.

_bootstrap/packages.txt

@@ -10,7 +10,6 @@ dialog
 docker
 dunst
 exa
-fakeroot
 fasd
 feh
 flashfocus-git
@@ -70,9 +69,10 @@ psmisc
 pulseaudio-alsa
 pulsemixer
 python-pdfminer.six
-python-pip
+python-pipx
 python-pybtex
 python-pynvim
+python-ueberzug
 qutebrowser
 redshift
 ripgrep-all
@@ -123,3 +123,13 @@ yarn
 yay
 youtube-dl
 zathura-pdf-mupdf
+pacman-contrib
+
+# zsh plugins
+oh-my-zsh-git
+alias-tips-git
+zsh-autosuggestions
+zsh-completions-git
+zsh-fast-syntax-highlighting-git
+zsh-theme-powerlevel10k-git
+nvm