Refactor: Add special deserializer for Vertex

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/datastructure/Vertex.java

@@ -21,6 +21,8 @@ package de.hft.stuttgart.citydoctor2.datastructure;
 import de.hft.stuttgart.citydoctor2.math.Vector3d;
 import de.hft.stuttgart.citydoctor2.utils.SerializablePair;
 
+import java.io.IOException;
+import java.io.ObjectInputStream;
 import java.io.Serial;
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -91,6 +93,12 @@ public class Vertex extends Vector3d {
         throw new IllegalStateException("Requested adjacent polygons with Geometry not containing this vertex");
     }
 
+    @Serial
+    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+        in.defaultReadObject();
+        clearAdjacentRings();
+    }
+
     public Set<Polygon> getAdjacentPolygons(Geometry geom) {
         return getAdjacentPolygonsWithoutNeighbor(geom);
     }