Add more Ruff rules (#891)

* ruff: apply rule F

* ruff: apply rule E

* ruff: apply rule SIM

* ruff: apply rule TCH

* ruff: apply rule ERA

* ruff: apply rule PLW

* ruff: apply rule FLY

* ruff: apply rule PERF

* ruff: apply rules FURB & RUF

club/models.py

@@ -389,9 +389,7 @@ class Membership(models.Model):
         if user.is_root or user.is_board_member:
             return True
         membership = self.club.get_membership_for(user)
-        if membership is not None and membership.role >= self.role:
-            return True
-        return False
+        return membership is not None and membership.role >= self.role
 
     def delete(self, *args, **kwargs):
         super().delete(*args, **kwargs)