Safari complains about invalid imagesrcset value in <link rel=prelo…

…ad> where Chrome doesn't

https://bugs.webkit.org/show_bug.cgi?id=231150
rdar://83891023

Reviewed by Brent Fulgham.

Enable the feature now that it is fully implemented.

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

Canonical link: https://commits.webkit.org/266787@main

Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml

@@ -3869,17 +3869,17 @@ LinkPreloadEnabled:
 
 LinkPreloadResponsiveImagesEnabled:
   type: bool
-  status: testable
+  status: stable
   category: networking
   humanReadableName: "Link preload responsive images"
   humanReadableDescription: "Enable link preload responsive images"
   defaultValue:
     WebKitLegacy:
-      default: false
+      default: true
     WebKit:
-      default: false
+      default: true
     WebCore:
-      default: false
+      default: true
 
 LinkSanitizerEnabled:
   type: bool