MM-67279: Fix private channel enumeration via /mute slash command (#35099) (#35149)

Automatic Merge

server/i18n/en.json

@@ -1241,10 +1241,6 @@
     "id": "api.command_mute.no_channel.error",
     "translation": "Could not find the specified channel. Please use the [channel handle](https://docs.mattermost.com/messaging/managing-channels.html#naming-a-channel) to identify channels."
   },
-  {
-    "id": "api.command_mute.not_member.error",
-    "translation": "Could not mute channel {{.Channel}} as you are not a member."
-  },
   {
     "id": "api.command_mute.success_mute",
     "translation": "You will not receive notifications for {{.Channel}} until channel mute is turned off."