help: Consistently name unsubscribe channel setting.

Remove question mark.
See https://chat.zulip.org/#narrow/channel/101-design/topic/name.20permissions.20settings.20consistently/near/1959774

help/configure-who-can-invite-to-channels.md

@@ -31,7 +31,7 @@ subscribed to the channel to configure these settings.
 {!select-channel-view-general.md!}
 
 1. Under **Channel permissions**, configure
-   **Who can unsubscribe others from this channel?**
+   **Who can unsubscribe others from this channel**
 
 {!save-changes.md!}
 

help/create-a-channel.md

@@ -33,7 +33,7 @@ There are several parameters you can set while creating a channel. All but
 
 * **Who can post to this channel**: See [Channel permissions](/help/channel-permissions).
 
-* **Who can unsubscribe others from this channel?**: See
+* **Who can unsubscribe others from this channel**: See
   [Restrict channel membership management](/help/configure-who-can-invite-to-channels#configure-who-can-remove-users).
 
 * **Message retention period**: See

tools/i18n/update-for-legacy-translations

@@ -158,7 +158,7 @@ LEGACY_STRINGS_MAP = {
     "Who can create web-public channels": "Who can create web-public streams",
     "Who can move messages to another channel": "Who can move messages to another stream",
     "Who can post to this channel": "Who can post to this stream",
-    "Who can unsubscribe others from this channel?": "Who can unsubscribe others from this stream?",
+    "Who can unsubscribe others from this channel": "Who can unsubscribe others from this stream",
     "You are not currently subscribed to this channel.": "You are not currently subscribed to this stream.",
     "You are not subscribed to any channels.": "You are not subscribed to any streams.",
     "You are not subscribed to channel <z-stream-name></z-stream-name>.": "You are not subscribed to stream <z-stream-name></z-stream-name>.",

web/templates/stream_settings/stream_types.hbs

@@ -68,7 +68,7 @@
 
         {{> ../dropdown_widget_with_label
           widget_name=can_remove_subscribers_setting_widget_name
-          label=(t 'Who can unsubscribe others from this channel?')
+          label=(t 'Who can unsubscribe others from this channel')
           value_type="number"}}
 
         {{#if (or is_owner is_stream_edit)}}