refactor: remove geerlingguy.docker dependency

Assume Docker and Docker Compose are already installed on the target
host. This decouples the role from a specific Docker installation
method; avoiding conflicts with existing setups.

meta/main.yaml

@@ -17,6 +17,4 @@ galaxy_info:
     - gitserver
     - selfhosted
 
-dependencies:
-  - role: geerlingguy.docker
-    version: "7.8.0"
+dependencies: []