I removed the webhook topic as highlighted here. However, it does not show up as removed in the Partner Shopify Dashboard Webhook metric section.
It kept on retrying to send the webhook from December 17 to December 18 which can be seen on the graph within the screenshot. I removed the webhook late in the night at December 18 and on December 19 (today as I'm posting this) and you can see the graph goes down which indicates that the removal of the webhook worked but it does not say it has been removed in dashboard. To be extra certain, I checked to see the list of available webhooks after deleting it and it didn't show anything either. It would show something after I registered a webhook so I know that logic is working fine.
Also, the graph shows that all the deliveries have failed but this cannot be true since I was able to save information from the webhook into my database and into a JSON file and did this several times. So the part in the partner dashboard in the screenshot that says failed delivery rate of 100% cannot be true.