Correct status of 'LiveRangeSelectionEnabled' from 'testable' to 'sta…

…ble'

https://bugs.webkit.org/show_bug.cgi?id=255306
<rdar://problem/107903680>

Reviewed by Ryosuke Niwa.

The LiveRangeSelectionEnabled feature is on by default on all targets, but is marked
with a status of 'testable'. We should display this as 'stable' as it is complete and
expected to be on in all deployments.

* Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml:

Canonical link: https://commits.webkit.org/262851@main

Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml

@@ -3685,7 +3685,7 @@ LinkSanitizerEnabled:
 
 LiveRangeSelectionEnabled:
   type: bool
-  status: testable
+  status: stable
   category: dom
   humanReadableName: "Live Ranges in Selection"
   humanReadableDescription: "Live range behavior for ranges in the Selection object"