Fix problem caused by PR #248 - startAt set in future with interval

[buzzinJohnnyBoi]

My previous pull request #248 did not take into account if startAt was in the future, as it would calculate the previous run as the startAt, which would cause the nextRun to appear to be in the future.
For this I sincerely apologize.
The fix for this is simply to check if the startAt is in the future. If this is the case, the previous run is not calculated.
Since including the if statement put the complexity of the _next function over 22, running npm run test:lint failed.
The solution to this was just to create a new function _calculatePreviousRun that will calculate the previous run only if startAt is in the past.
I also added a test in test/node/js/src/suites/options.cjs to prove that this was working.

[buzzinJohnnyBoi]

Not quite sure why the tests are failing, npm run build:ci passes on my local machine

[buzzinJohnnyBoi]

I added 3 lines of comments and the tests pass now, I guess sometimes they just need to be run again :)

[Hexagon]

Looking good! The tests does that sometimes 🥳