Fix error message about unknown `ActiveJob` argument serializer

activejob/lib/active_job/serializers.rb

@@ -38,7 +38,7 @@ module ActiveJob
         raise ArgumentError, "Serializer name is not present in the argument: #{argument.inspect}" unless serializer_name
 
         serializer = serializer_name.safe_constantize
-        raise ArgumentError, "Serializer #{serializer_name} is not know" unless serializer
+        raise ArgumentError, "Serializer #{serializer_name} is not known" unless serializer
 
         serializer.deserialize(argument)
       end

activejob/test/cases/serializers_test.rb

@@ -73,7 +73,7 @@ class SerializersTest < ActiveSupport::TestCase
       ActiveJob::Serializers.deserialize(hash)
     end
     assert_equal(
-      "Serializer DoNotExist is not know",
+      "Serializer DoNotExist is not known",
       error.message
     )
   end