modules: packages: desktop: add alacritty for test run

Description

As discuss with @pagnou_p, @dumeig_a @dudin_b, @enzo.bouriche, introduce the Alacritty terminal emulator for a beta testing.

• fix i3-desktop tests

also fix the test pipeline

TODO

• sign
• test vm
• fix epita-login test

Implication

if the test run is successfully deprecate totally urxvt