Use endless method definition in `UseCase::Base`

Co-authored-by: Georg Gadinger <nilsding@nilsding.org>

lib/use_case/base.rb

@@ -8,12 +8,8 @@ module UseCase
   class Base
     extend Dry::Initializer
 
-    def self.call(...)
+    def self.call(...) = new(...).call
-      new(...).call
-    end
 
-    def call
+    def call = raise NotImplementedError
-      raise NotImplementedError
-    end
   end
 end