Transceiver memory leak (#751)

Resolves #420

Author: pblazej

.changes/transceiver-leak

@@ -0,0 +1 @@
+patch type="fixed" "Fixed memory leak while unpublishing video tracks"

Sources/LiveKit/Core/Transport.swift

@@ -323,6 +323,11 @@ extension Transport {
     }
 
     func remove(track sender: LKRTCRtpSender) throws {
+        // Stop the transceiver to release its resources and prevent memory leak
+        if let transceiver = _pc.transceivers.first(where: { $0.sender == sender }) {
+            transceiver.stopInternal()
+        }
+
         guard _pc.removeTrack(sender) else {
             throw LiveKitError(.webRTC, message: "Failed to remove track")
         }