Install packages needed to build our website in tails::weblate

Originally created by @intrigeri on #12221 (Redmine)

We already have that list in the ISO builder Puppet class, I’m gonna refactor, extract it so we can use the same list for ISO builders and for the weblate VM.

Parent Task: #11759 (closed)

Edited May 15, 2020 by intrigeri

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information