Move from gitea to forgejo

Moved all variables over; moved git passthrough script to new location
and naming scheme; moved settings and mentions of gitea name; switched
ci woodpecker instance to use forgejo instead of gitea.

roles/gitea/vars/main.yml

@@ -1,9 +1,9 @@
 ---
 
-stack_name: gitea
+stack_name: forgejo
 
-stack_image: "gitea/gitea"
+stack_image: "codeberg.org/forgejo/forgejo"
 
 stack_compose: "{{ lookup('template', 'docker-stack.yml.j2') | from_yaml }}"
 
-gitea_git_username: git
+forgejo_git_username: git