Enable Scroll To Text Fragment by default.

https://bugs.webkit.org/show_bug.cgi?id=244351

Reviewed by Wenson Hsieh.

Set scroll to text fragment to default to on.
We do not currently implement this in legacy webkit so don't bother
defaulting to on in that case.

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

Canonical link: https://commits.webkit.org/253855@main

Source/WTF/Scripts/Preferences/WebPreferencesExperimental.yaml

@@ -1389,9 +1389,9 @@ ScrollToTextFragmentEnabled:
     WebKitLegacy:
       default: false
     WebKit:
-      default: false
+      default: true
     WebCore:
-      default: false
+      default: true
 
 ServerTimingEnabled:
   type: bool