fix: fix open tickets count

[VinDotRun]

Versioning information

• [ ] This includes major changes (breaking changes)
• [ ] This includes minor changes (minimal usage changes, minor new features)
• [X] This includes patches (bug fixes)
• [ ] This does not change functionality at all (code refactoring, comments)

Is this related to an issue?

Fixes #499

Changes made

In the ready client listener, renamed the pre-existing closedTickets variable to closedTicketsWithResponse. Alongside this variable, added a new one with the previous name of closedTickets. This new variable filters tickets by ticket.closedAt, instead of ticket.firstResponseAt && ticket.closedAt. This allows the placeholder {openTickets} in the bot's presence to display accurate information.

Confirmations

• [ ] I have updated related documentation (if necessary)
• [X] My changes use consistent code style
• [X] My changes have been tested and confirmed to work

[eartharoid]

@all-contributors please add @VinDotRun for bug and code

[allcontributors[bot]]

@eartharoid

I've put up a pull request to add @VinDotRun! :tada: