feat: limit s3_web to gateway in gateway-enable cluster or to every node in gateway-less cluster

roles/garage/templates/garage.toml.j2

@@ -1,3 +1,9 @@
+{%
+set s3_web = '
+[s3_web]
+bind_addr = "[::1]:3902"
+root_domain = "%s"'
+-%}
 metadata_dir = "/var/lib/garage/meta"
 data_dir = "/var/lib/garage/data"
 db_engine = "lmdb"
@@ -14,7 +20,10 @@ rpc_secret = "{{ garage_rpc_secret }}"
 s3_region = "garage"
 api_bind_addr = "[::]:3900"
 root_domain = "{{ garage_root_domain }}"
-
-[s3_web]
-bind_addr = "[::1]:3902"
-root_domain = "{{ garage_root_domain }}"
+{% if (groups[cluster_group] | select('search', '.+gw.+') | list | length > 0) %}
+{% if 'gw' in inventory_hostname %}
+{{ s3_web % garage_root_domain }}
+{% endif %}
+{% else %}
+{{ s3_web % garage_root_domain }}
+{% endif %}