make the transport discovery lk edgecase a EC exclusive workaround

Dont add it to the sdk.

sdk/src/media-backend/api.ts

@@ -13,10 +13,7 @@ Please see LICENSE in the repository root for full details.
  */
 
 import { type Logger } from "matrix-js-sdk/lib/logger";
-import {
-  type CallMembership,
-  type Transport,
-} from "matrix-js-sdk/lib/matrixrtc";
+import { type Transport } from "matrix-js-sdk/lib/matrixrtc";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 import { type Observable } from "rxjs";
 
@@ -119,17 +116,6 @@ export interface MediaBackend {
   /** The membership transport type this backend serves: "livekit". */
   readonly transportType: string;
 
-  /**
-   * A transport to publish on where neither the homeserver nor the host
-   * provides one of the backend's type: for LiveKit, the SFU of another
-   * member whose homeserver lets us publish on it (MSC4195). Resolves null
-   * where no member's transport will do. Called at most once per session,
-   * with the memberships at that moment, before `prepareLocalTransport`.
-   */
-  findRemotePublishTransport(
-    memberships: CallMembership[],
-  ): Promise<Transport | null>;
-
   /**
    * Makes `transport` usable as the one the local member publishes on. The
    * session found it; the backend does whatever has to succeed before it is