fix: [Backport] Ensure NetworkConnectionManager correctly handles multiple disconnect messages being sent#3721

EmandM merged 5 commits intodevelopUnity-Technologies/com.unity.netcode.gameobjects:developfrom

fix/1.x/transport-double-disconnectUnity-Technologies/com.unity.netcode.gameobjects:fix/1.x/transport-double-disconnectCopy head branch name to clipboard