"shepherd-enabled" class is not removed from body element when tour ends

[IWMTom]

Reproducible on the Shepherd demo site: https://shepherdjs.dev/

Reach the end of the demo and inspect the body element - "shepherd-enabled" will still be set.

This is causing an issue in a project where we disable some scrollbars on certain elements if shepherd-enabled is set on the body. As it's never removed, the scrollbars remain disabled when the tour has been completed/cancelled.

[IWMTom]

After further debugging, the issue seems to occur when a step isn't attached to a specific element (i.e. we want the modal to be centered on the screen, either as an introductory or final step).

I believe it may be due to the fact in _show(), the target used to add the class has a fallback:
const target = this.target || document.body

However in _updateStepTargetOnHide() there is no fallback, and this.target is referred to directly. Presumably this is why the class is never removed from the body element.

[RobbieTheWagner]

@IWMTom thanks for reporting this! Sounds like you have a good idea of what could be wrong. Would you like to open a PR to fix it?

[IWMTom]

@IWMTom thanks for reporting this! Sounds like you have a good idea of what could be wrong. Would you like to open a PR to fix it?

Happy to! Will revert back with a PR this evening.