remove redundant feature gate

Author: Jiloc

clarity-serialization/src/tests/mod.rs

@@ -13,8 +13,6 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-#![cfg(any(test, feature = "testing"))]
-
 use stacks_common::address::{AddressHashMode, C32_ADDRESS_VERSION_TESTNET_SINGLESIG};
 use stacks_common::types::chainstate::{StacksAddress, StacksPrivateKey, StacksPublicKey};