spec: remove cycle restriction for type parameters

// This program demonstrates the cycle restriction that will be removed in a future Go release.
// The commented code below would compile after the change, but currently fails to compile
// with Go 1.27.1 because a type constraint may not refer to its own type parameter list.

package main

import "fmt"

func main() {
	fmt.Println("Cycle restriction removed in future Go releases.")
}

/*
// Example of a self‑referencing generic type that is now allowed:
//
// type Node[T any] struct {
//     Value T
//     Children []Tree[T] // refers to Tree, which refers back to Node
// }
//
// type Tree[T any] struct {
//     Root Node[T]
// }
*/