remove redundant connectionLookup entries

packages/svelte/src/lib/components/Handle/Handle.svelte

@@ -116,7 +116,7 @@
   $: if (onconnect || ondisconnect) {
     // connectionLookup is not reactive, so we use edges to get notified about updates
     $edges;
-    connections = $connectionLookup.get(`${nodeId}-${type}-${id || null}`);
+    connections = $connectionLookup.get(`${nodeId}-${type}${id ? `-${id}` : ''}`);
   }
 
   $: {

packages/svelte/src/lib/hooks/useHandleConnections.ts

@@ -22,7 +22,7 @@ const initialConnections: HandleConnection[] = [];
  * @param param.id - the handle id (this is only needed if the node has multiple handles of the same type)
  * @returns an array with connections
  */
-export function useHandleConnections({ type, nodeId, id = null }: useHandleConnectionsParams) {
+export function useHandleConnections({ type, nodeId, id }: useHandleConnectionsParams) {
   const { edges, connectionLookup } = useStore();
 
   console.warn(
@@ -37,7 +37,7 @@ export function useHandleConnections({ type, nodeId, id = null }: useHandleConne
   return derived(
     [edges, connectionLookup],
     ([, connectionLookup], set) => {
-      const nextConnections = connectionLookup.get(`${currentNodeId}-${type}-${id || null}`);
+      const nextConnections = connectionLookup.get(`${currentNodeId}-${type}${id ? `-${id}` : ''}`);
 
       if (!areConnectionMapsEqual(nextConnections, prevConnections)) {
         prevConnections = nextConnections;