[ruby/openssl] test_pkcs12.rb: don't use KEY_EX/SIG with AWS-LC

AWS-LC does not support the KEY_SIG or KEY_EX flags that were only ever
supported by old MSIE.

ruby/openssl@d50528b4e2

Author: samuel40791765

test/openssl/test_pkcs12.rb

@@ -178,6 +178,8 @@ def test_create_with_mac_itr
     end
 
     def test_create_with_keytype
+      omit "AWS-LC does not support KEY_SIG and KEY_EX" if aws_lc?
+
       OpenSSL::PKCS12.create(
         "omg",
         "hello",