fix(workspaces): dont leak guests

[gjedlicska]

Description & motivation

Changes:

To-do before merge:

Screenshots:

Validation of changes:

Checklist:

• My pull request follows the guidelines in the Contributing guide?
• My pull request does not duplicate any other open Pull Requests for the same update/change?
• My commits are related to the pull request and do not amend unrelated code or documentation.
• My code follows a similar style to existing code.
• I have added appropriate tests.
• I have updated or added relevant documentation.

References

[linear]

WEB-1763 Workspace billing guests leak

[gjedlicska]

@alemagio for your retroactive review too, we were leaking guests between workspaces, if the user had a member role on wsA and a guest role on wsB, they would show up as both a guest and a member on wsA billing