Reach capabilities of function arguments get ignored

[Linyxus]

Compiler version

main

Minimized code

import language.experimental.captureChecking
def runOps(ops: List[() => Unit]): Unit =
  ops.foreach(op => op())

def main(): Unit =
  val f: List[() => Unit] -> Unit = runOps  // should be error

Output

It compiles.

Expectation

It should not, as runOps unboxes the list elements and executes them, so runOps should not be pure. Based on the theory, we should simply prevent runOps from typechecking.

[Linyxus]

related: #19571, cc @odersky