FIX!: update ruby verion (3.0.3 instead off 2.7.1)

requires a DS software version
greater than or equal to 2021-11-30-02
see: https://github.com/betagouv/demarches-simplifiees.fr/releases/tag/2021-11-30-02)

Refs: #34

manifests/default.pp

@@ -157,7 +157,7 @@ class { 'rbenv':
   owner       => $_system_username,
 }
 rbenv::plugin { 'rbenv/ruby-build': }
--> rbenv::build { '2.7.1': global => true }
+-> rbenv::build { '3.0.3': global => true }
 
 # Ensure permissions on /usr/bin/env
 -> file { '/usr/bin/env':