[v11.0.x] Canvas: Fix phantom connections persisting after element deletion (#87355)

Canvas: Fix phantom connections persisting after element deletion (#87285)

(cherry picked from commit 68fa2110d6)

Co-authored-by: Nathan Marrs <nathanielmarrs@gmail.com>

public/app/plugins/panel/canvas/utils.ts

@@ -320,6 +320,9 @@ export function updateConnectionsForSource(element: ElementState, scene: Scene)
     const connections = sourceConnections.filter((con) => con.targetName !== element.getName());
     connection.source.onChange({ ...connection.source.options, connections });
   });
+
+  // Update scene connection state to clear out old connections
+  scene.connections.updateState();
 }
 
 export const calculateCoordinates = (