sinon not throwing the error that been thrown when the error is undefined and also fail to assert

Describe the bug
If the function throw undefined then:

1. calling the function does not throw
2. sinon.assert.threw(a); fail

To Reproduce
ReplIt Link

const a = sinon.spy(() => {
  throw undefined;
});

try {
  a();
} catch (e) {
   // 1. this won't be logged
  console.log('Error has being thrown');
}

// 2. This will throw
// Uncaught AssertError: spy did not throw exception
sinon.assert.threw(a);

Expected behavior

1. throw the thrown error
2. the assertion should pass

As said in the docs about the 2nd thing:

sinon.assert.threw(spyOrSpyCall, exception);

Passes if spy threw the given exception.

The exception can be a String denoting its type, or an actual object.

If only one argument is provided, the assertion passes if spy ever threw any exception.

Context (please complete the following information):

• Library version: 14.0.0
• Environment: node

Start with the JavaScript reproduction in the linked Replit example and trace how the spy records a thrown undefined value and how sinon.assert.threw checks it. Confirm both expected behaviors: the original call propagates the thrown value and the assertion passes when any exception was thrown.