workstation: remove i3

i3 conflicts with i3-gaps. i3-gaps should follow upstream i3 with a few
extra features. Remove i3 and keep i3-gaps for now.

manifests/workstation.pp

@@ -68,7 +68,6 @@ class freebsd::workstation inherits freebsd::base {
       'hs-pandoc',
       'hs-xmonad',
       'htop',
-      'i3',
       'i3-gaps',
       'i3status',
       'icecast',