Migrate to fontawesome 6

app/views/layouts/_admin_sidebar_index.html.haml

@@ -1,44 +1,44 @@
 %ul.nav.nav-stacked.nav-pills.mySidebar.collapse.navbar-collapse#side-nav
   .btn-group
     %button{type: 'button', class: 'btn btn-default btn-link dropdown-toggle', 'data-toggle'=>'dropdown'}
-      %span.fa.fa-home
+      %span.fa-solid.fa-house
       All Conferences
       %span.caret
     %ul.dropdown-menu{role: 'menu'}
       %li
         = link_to(admin_conferences_path) do
-          %span.fa.fa-home
+          %span.fa-solid.fa-house
           All Conferences
       - @conferences.each do |conference|
         - if can? :show, conference
           %li
             = link_to(admin_conference_path(conference.short_title)) do
-              %span.fa.fa-cog
+              %span.fa-solid.fa-gear
               Manage
               = conference.short_title
       - if can? :new, Conference.new
         %li
           = link_to(new_admin_conference_path) do
-            %span.fa.fa-plus
+            %span.fa-solid.fa-plus
             New Conference
   - if can? :index, User
     %hr
     %li
       = link_to(admin_users_path) do
-        %span.fa.fa-user
+        %span.fa-solid.fa-user
         Users
   - if can? :index, Organization
     %li
       = link_to(admin_organizations_path) do
-        %span.fa.fa-users
+        %span.fa-solid.fa-users
         Organizations
   - if can? :index, PaperTrail::Version
     %li
       = link_to(admin_revision_history_path) do
-        %span.fa.fa-history
+        %span.fa-solid.fa-clock-rotate-left
         Revision History
     - if ENV.fetch('ORGANIZATIONS_ENABLED', nil) == 'true'
       %li
         = link_to(admin_organizations_path) do
-          %span.fa.fa-group
+          %span.fa-solid.fa-user-group
           Organizations