Fix swh-jenkins/base-buster docker image build
This image is not building since january due to a wrong gpg key for the yarn repository
13:29:19 #9 11.19 W: GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 23E7166788B63E1EA new version of this image is needed to test D5232
https://jenkins.softwareheritage.org/job/jenkins-tools/job/swh-jenkins-dockerfiles/
Migrated from T3120 (view on Phabricator)