Dont create dev cert if certificate is not explicitly specified

[Swiip]

Hey, thanks for the work you're doing.

In my project, we use the https://github.com/electron/windows-sign automaticallySelectCertificate option and leave the administration of the certificate to the owner of the ci runner.

Unfortunately, unless I missed something, in msix maker, if I don't explicitly specify a certificate file, it triggers the creation of a dev certificate which kind of makes sense but blocks me.

I would like to suggest to add a way with configuration to be able to not have a certificateFile while not using the dev cert.

This PR suggest a simple way, instead of activating the dev cert only with certificateFile prop being set, deactivate dev cert if any windowsSignOptions are set. At least it works for me (I plugged my fork for now). What do you think?