Improve the logic in AccessRequestsFinder#execute & #execute!

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/finders/access_requests_finder.rb

@@ -7,23 +7,21 @@ class AccessRequestsFinder
     @source = source
   end
 
-  def execute(current_user, raise_error: false)
-    if cannot_see_access_requests?(current_user)
-      raise Gitlab::Access::AccessDeniedError if raise_error
-
-      return []
-    end
-
-    source.requesters
+  def execute(*args)
+    execute!(*args)
+  rescue Gitlab::Access::AccessDeniedError
+    []
   end
 
   def execute!(current_user)
-    execute(current_user, raise_error: true)
+    raise Gitlab::Access::AccessDeniedError unless can_see_access_requests?(current_user)
+
+    source.requesters
   end
 
   private
 
-  def cannot_see_access_requests?(current_user)
-    !source || !current_user || !current_user.can?(:"admin_#{source.class.to_s.underscore}", source)
+  def can_see_access_requests?(current_user)
+    source && current_user && current_user.can?(:"admin_#{source.class.to_s.underscore}", source)
   end
 end