Update jenkins-slave to docker 20.10.11 and yarn 1.22.15

jenkins-slave = https://github.com/folio-org/folio-tools/blob/master/jenkins-slave-docker/Dockerfile.focal-java-11

Updating docker from 20.10.7 to 20.10.11 fixes these security issues:

• https://docs.docker.com/engine/release-notes/
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-36221
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-39293
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41089
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41091
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41092
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41103
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41190

Updating yarn from 1.22.5 to 1.22.15 gives the latest stable 1.22 release with bugfixes.