Libraries: Use AK::Variant default initialization where appropriate

Author: https://github.com/BenWiederhake
Commit: 32e98d0924
Pull-request: https://github.com/SerenityOS/serenity/pull/10154
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h

@@ -352,7 +352,7 @@ private:
     // Type::Comment (comment data), Type::StartTag and Type::EndTag (tag name)
     String m_string_data;
 
-    Variant<Empty, u32, OwnPtr<DoctypeData>, OwnPtr<Vector<Attribute>>> m_data { Empty {} };
+    Variant<Empty, u32, OwnPtr<DoctypeData>, OwnPtr<Vector<Attribute>>> m_data {};
 
     Position m_start_position;
     Position m_end_position;