alloy(role): remove alloy_config_default contents from role

alloy_config_default should be set in group vars

roles/alloy/defaults/main.yaml

@@ -1,49 +1,7 @@
 ---
 alloy_cap_net_bind_service: false
 
-alloy_config_default: |
+alloy_config_default: ""
-  prometheus.remote_write "default" {
-    endpoint {
-      url = "https://metrics.hamburg.ccc.de/api/v1/write"
-      basic_auth {
-        username = "chaos"
-        password = "{{ metrics__chaos_password }}"
-      }
-    }
-  }
-
-  prometheus.relabel "chaosknoten_common" {
-    forward_to = [prometheus.remote_write.default.receiver]
-    rule {
-      target_label = "org"
-      replacement = "ccchh"
-    }
-    rule {
-      target_label = "site"
-      replacement = "wieske"
-    }
-    rule {
-      source_labels = ["instance"]
-      target_label = "instance"
-      regex  = "([^:]+)"
-      replacement = "${1}.hosts.hamburg.ccc.de"
-      action = "replace"
-    }
-  }
-
-  logging {
-    level = "info"
-  }
-
-  prometheus.exporter.unix "local_system" {
-    enable_collectors = ["systemd"]
-  }
-
-  prometheus.scrape "scrape_metrics" {
-    targets           = prometheus.exporter.unix.local_system.targets
-    forward_to        = [prometheus.relabel.chaosknoten_common.receiver]
-  }
-
 alloy_config_additional: ""
 
 alloy_blackbox_exporter_config_default: |