Object.defineProperty is updated to lazily load the undici dependency
for the fetch method. This change allows for simpler and more reliable
mocking of the fetch method for testing purposes, resolving issues
encountered with premature method invocation during testing.

Fixes: nodejs#52015

Instead of importing undici upfront, the module is now conditionally
required using require only when the fetch function is called for the
first time and the undici implementation is not already available. This
lazy loading approach improves resource usage and test reliability by
loading undici only when needed.

The purpose of this test is to verify the correct behavior of stubbing
the globalThis.fetch method with custom implementation. It checks
whether the stubbed fetch function correctly returns the expected
response without calling fetch iteself first.