add plugin release webhook notification

[cibere]

Based on #420

This PR adds a notification that gets triggered in the python-passed.yml workflow, where when the DateAdded key gets added to a plugin, a notification is sent to discord stating that a new plugin has been uploaded. I tried to keep the embed similar to the one used for updates, but I made a couple of changes.

Notification Example

Overview of changes

1. Added requirements to the update-tested.py script and python-passed.yml workflow
2. added a release_hook function based on update_hook to discord.py
3. have update-tested.py execute release_hook for new releases
4. Added webhook_url to update-tested.py via a CLI argument
5. I also fixed a couple of typehints so that my typechecker would stop yelling at me

[cibere]

I also reverted most of the changes I made to send_notification and opted to interact directly with release_hook, since release_hook and send_notification take different parameters now.

[cibere]

I decided to move send_notification back to updater.py since it's no longer being used in update-tested.py, and there are 2 discord webhook hooks in discord.py

[jjw24]

👍