Remove unused variable

Author: NewThinker-Jeffrey

gtsam_unstable/nonlinear/BayesTreeMarginalizationHelper.h

@@ -70,7 +70,6 @@ class GTSAM_UNSTABLE_EXPORT BayesTreeMarginalizationHelper {
     std::set<Key> additionalKeys;
     std::set<Key> marginalizableKeySet(
         marginalizableKeys.begin(), marginalizableKeys.end());
-    std::set<sharedClique> dependentCliques;
     CachedSearch cachedSearch;
 
     // Check each clique that contains a marginalizable key