Fix initializer list initialization for GCC-15 (#5443)

include/xrpl/beast/hash/uhash.h

@@ -30,7 +30,7 @@ namespace beast {
 template <class Hasher = xxhasher>
 struct uhash
 {
-    explicit uhash() = default;
+    uhash() = default;
 
     using result_type = typename Hasher::result_type;