Allow filename argument to lack tape extension

[DaltonSW]

Describe your changes

Related issue/discussion:

Checklist before requesting a review

• [x] I have read CONTRIBUTING.md
• [x] I have performed a self-review of my code

If this is a feature

• [x] I have created a discussion
• [ ] A project maintainer has approved this feature request.
  • Haven't gotten a response here or in Discord. This feels small enough to discuss here if needed :)