Fix checkstyle

Author: s1ck

graph-schema-api/src/main/java/org/neo4j/gds/api/schema/RelationshipSchema.java

@@ -23,7 +23,6 @@
 import org.neo4j.gds.api.PropertyState;
 import org.neo4j.gds.api.nodeproperties.ValueType;
 
-import javax.management.relation.Relation;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;