Bump foucoco spec version to `20`#496

ebma wants to merge 3 commits intomainpendulum-chain/pendulum:mainfrom

495-bump-spec_version-for-foucoco-to-20-and-deploy-new-runtime-upgradependulum-chain/pendulum:495-bump-spec_version-for-foucoco-to-20-and-deploy-new-runtime-upgradeCopy head branch name to clipboard