chore: I have no fucking idea

This is vibecoded shit but i can't be bothered to do it myself.
Nobody else besides me is gonna be using this, and this wont ever be
extended or anything, so I just don't care.

database.go

@@ -104,3 +104,8 @@ func (d *Database) SetBridge(ntfyTopic, matrixRoomID string) error {
 	)
 	return err
 }
+
+func (d *Database) DeleteBridge(ntfyTopic string) error {
+	_, err := d.db.Exec("DELETE FROM bridges WHERE ntfy_topic = ?", ntfyTopic)
+	return err
+}