Add repository default label changed event

proto/buf/alpha/audit/v1alpha1/event.proto

@@ -86,6 +86,7 @@ enum EventType {
   EVENT_TYPE_REPOSITORY_CONTRIBUTOR_ROLE_CHANGED = 10;
   EVENT_TYPE_REPOSITORY_CONTRIBUTOR_REMOVED = 11;
   EVENT_TYPE_REPOSITORY_VISIBILITY_CHANGED = 12;
+  EVENT_TYPE_REPOSITORY_DEFAULT_LABEL_NAME_CHANGED = 40;
   EVENT_TYPE_PLUGIN_CREATED = 13 [deprecated = true];
   EVENT_TYPE_PLUGIN_DELETED = 14 [deprecated = true];
   EVENT_TYPE_CURATED_PLUGIN_CREATED = 20;
@@ -156,6 +157,7 @@ message Event {
     PayloadRepositoryContributorRoleChanged repository_contributor_role_changed = 16;
     PayloadRepositoryContributorRemoved repository_contributor_removed = 17;
     PayloadRepositoryVisibilityChanged repository_visibility_changed = 18;
+    PayloadRepositoryDefaultLabelNameChanged repository_default_label_name_changed = 46;
     PayloadUserCreated user_created = 21;
     PayloadUserDeactivated user_deactivated = 22;
     PayloadUserDeleted user_deleted = 23;
@@ -331,6 +333,17 @@ message PayloadRepositoryVisibilityChanged {
   buf.alpha.registry.v1alpha1.Visibility new_visibility = 4;
 }
 
+message PayloadRepositoryDefaultLabelNameChanged {
+  // owner_id is the id of the owner of the repository.
+  string owner_id = 1;
+  // owner_name is the name of the owner of the repository.
+  string owner_name = 2;
+  // old_default_label_name is the old default label name of the repository.
+  string old_default_label_name = 3;
+  // new_default_label_name is the new default label name of the repository.
+  string new_default_label_name = 4;
+}
+
 message PayloadRepositoryDefaultBranchChanged {
   // owner_id is the id of the owner of the repository.
   string owner_id = 1;