build: make configure --without-snapshot a no-op

From V8 7.9, the option will no longer exist upstream.

Refs: https://chromium-review.googlesource.com/c/chromium/src/+/1796325

I don't know if we need to make this semver-major, but I really want to land this in v13.x to allow updating V8 later on that branch.

/cc @nodejs/v8-update @joyeecheung