Treat code-size warnings as errors (#5101)

Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>

hardhat.config.js

@@ -90,7 +90,6 @@ module.exports = {
       'initcode-size': 'off',
     },
     '*': {
-      'code-size': true,
       'unused-param': !argv.coverage, // coverage causes unused-param warnings
       'transient-storage': false,
       default: 'error',