Rely on state change to cancel future

Author: AndrewFerr

src/matrixrtc/MatrixRTCSession.ts

@@ -138,8 +138,6 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
     private encryptionKeys = new Map<string, Array<Uint8Array>>();
     private lastEncryptionKeyUpdateRequest?: number;
 
-    private disconnectFutureId: string | undefined;
-
     /**
      * The callId (sessionId) of the call.
      *
@@ -891,19 +889,11 @@ export class MatrixRTCSession extends TypedEventEmitter<MatrixRTCSessionEvent, M
                             {}, // leave event
                             stateKey,
                         );
-                        this.disconnectFutureId = res.future_id;
                         this.scheduleRefreshFuture(res.future_id);
                     } catch (e) {
                         logger.error("Failed to send future:", e);
                     }
                 }
-            } else if (!legacy && this.disconnectFutureId !== undefined) {
-                // TODO: remove this once the Synapse MSC4140 implementation cancels timeout futures on state change
-                try {
-                    await this.client._unstable_updateFuture(this.disconnectFutureId, UpdateFutureAction.Cancel);
-                } catch (e) {
-                    logger.error("Failed to cancel future:", e);
-                }
             }
         } catch (e) {
             const resendDelay = CALL_MEMBER_EVENT_RETRY_DELAY_MIN + Math.random() * 2000;