Use reticulum as the docker repository instead of ret

It was decided that continuing to use ret is too obscure and that now is the time to change it before too much history builds up.

Corresponding change for the Community Edition: Hubs-Foundation/hubs-cloud#366

.github/workflows/ret-turkey.yml

@@ -1,4 +1,4 @@
-name: ret
+name: reticulum
 on:
   push:
     branches: