
As per above - ServiceNow is an (ITIL based) Service Management Tool.
Arguably a pretty decent one. But it has no functionality (or even the concept) of software/file version management.
Its various process records can have (file) attachments etc (and complex process driven interactions).
It could be customised to have pretty good process control over your development process and it could support your Version Management (SCM) process and even possibly have links into VM tools (all or most of the usual suspects).