fix circular import

Author: toger5

src/matrixrtc/MembershipManager.ts

@@ -1,7 +1,8 @@
 import { UpdateDelayedEventAction } from "../@types/requests.ts";
 import { HTTPError, MatrixError } from "../http-api/errors.ts";
 import { logger } from "../logger.ts";
-import { EventTimeline, EventType, MatrixClient, Room } from "../matrix.ts";
+import { EventTimeline, EventType } from "../matrix.ts";
+import type { MatrixClient, Room } from "../matrix.ts";
 import { sleep } from "../utils.ts";
 import { CallMembership, DEFAULT_EXPIRE_DURATION, SessionMembershipData } from "./CallMembership.ts";
 import { Focus } from "./focus.ts";