Merge pull request #10068 from Habbie/no-more-yum

docker builds: stop using yum on EL8 derivatives

diff --cc builder-support/dockerfiles/Dockerfile.target.centos-8
index ee8cc74f3751fb8bf3cbc96bd016e0366579edb1,cc25e21bdc6ce0630a4c86537883fb7fb0e68602..bd206d0cd4992c65dd6632d47814edc829a4655c
--- 1/builder-support/dockerfiles/Dockerfile.target.centos-8
--- 2/builder-support/dockerfiles/Dockerfile.target.centos-8
+++ b/builder-support/dockerfiles/Dockerfile.target.centos-8
@@@ -3,17 -3,9 +3,17 @@@
  
  # This defines the distribution base layer
  # Put only the bare minimum of common commands here, without dev tools
 +@IF [ ${BUILDER_TARGET} = centos-8 ]
  FROM centos:8 as dist-base
 +@ENDIF
 +@IF [ ${BUILDER_TARGET} = centos-8-amd64 ]
 +FROM amd64/centos:8 as dist-base
 +@ENDIF
 +@IF [ ${BUILDER_TARGET} = centos-8-arm64 ]
 +FROM arm64v8/centos:8 as dist-base
 +@ENDIF
  ARG BUILDER_CACHE_BUSTER=
- RUN touch /var/lib/rpm/* && yum install -y epel-release && \
+ RUN touch /var/lib/rpm/* && dnf install -y epel-release && \
      dnf install -y 'dnf-command(config-manager)' && \
      dnf config-manager --set-enabled powertools