features: change metrics registration logic

Author: WillemKauf

src/v/features/feature_table.cc

@@ -384,7 +384,9 @@ feature_table::feature_table() {
             }
         }
     }
+}
 
+void feature_table::setup_metrics() {
     _probe = std::make_unique<probe>(*this);
     _probe->setup_metrics();
 }

src/v/features/feature_table.h

@@ -662,7 +662,7 @@ class feature_table {
     std::optional<feature> resolve_name(std::string_view feature_name) const;
 
     void set_license(security::license license);
-
+    void setup_metrics();
     /// Sets the builtin trial license based on the cluster creation time
     void set_builtin_trial_license(model::timestamp cluster_creation_timestamp);