removed compatibility with old format, small fix in editor

frontend/src/Editor.svelte

@@ -242,7 +242,6 @@
 
 <Graph
   {tasks}
-  {repulsionForce}
   on:selectTask={clickTask}
   on:preSelectTask={startHovering}
   bind:this={graph}

frontend/src/tasks.ts

@@ -50,14 +50,6 @@ export function createEdges(nodes: TaskDescriptor[]): TaskEdge[] {
 export async function loadTasks(): Promise<TasksFile> {
     const r = await fetch("/tasks.json")
     const j = await r.json()
-
-    // backward compatibility
-    if (j.positions != null) {
-        for (const [id,  pos] of Object.entries(j.positions)) {
-            j.tasks.find((t) => t.id == id).position = pos;
-        }
-    }
-     
     return j
 }