docker: small fix-ups for UBI9 containers (#4335)

Do following fix-ups pointed out on #4280:

- Use Red Hat registry for UBI image
- Minimize layers
- Run cleanup of microdnf

fixes #4280

Signed-off-by: Takuya ASADA <[email protected]>
(cherry picked from commit bae8518)

Author: syuu1228

Diff for: dist/docker/scylla-manager-agent.dockerfile

@@ -1,14 +1,15 @@
-FROM docker.io/redhat/ubi9-minimal:latest
+FROM registry.access.redhat.com/ubi9-minimal:latest
 ARG ARCH=x86_64
 
+COPY release/scylla-manager-agent*$ARCH.rpm /
+COPY license/LICENSE.* /licenses/
+
 RUN microdnf -y update && \
     microdnf -y upgrade && \
     microdnf install -y ca-certificates && \
-    rm -rf /var/lib/apt/lists/*
-
-COPY release/scylla-manager-agent*$ARCH.rpm /
-RUN rpm -ivh scylla-manager-agent*$ARCH.rpm && rm /scylla-manager-agent*.rpm
-COPY license/LICENSE.* /licenses/
+    microdnf clean all && \
+    rpm -ivh scylla-manager-agent*$ARCH.rpm && \
+    rm /scylla-manager-agent*.rpm
 
 USER scylla-manager
 ENV HOME=/var/lib/scylla-manager/

Diff for: dist/docker/scylla-manager.dockerfile

@@ -1,16 +1,17 @@
-FROM docker.io/redhat/ubi9-minimal:latest
+FROM registry.access.redhat.com/ubi9-minimal:latest
 ARG ARCH=x86_64
 
-RUN microdnf -y update && \
-    microdnf -y upgrade && \
-    microdnf install -y ca-certificates && \
-    rm -rf /var/lib/apt/lists/*
-
 COPY release/scylla-manager-*$ARCH.rpm /
-RUN rpm -ivh scylla-manager-*$ARCH.rpm && rm /scylla-manager-*.rpm
 COPY docker/scylla-manager.yaml /etc/scylla-manager/
 COPY license/LICENSE.* /licenses/
 
+RUN microdnf -y update && \
+    microdnf -y upgrade && \
+    microdnf install -y ca-certificates && \
+    microdnf clean all && \
+    rpm -ivh scylla-manager-*$ARCH.rpm && \
+    rm /scylla-manager-*.rpm
+
 USER scylla-manager
 ENV HOME=/var/lib/scylla-manager/
 ENTRYPOINT ["/usr/bin/scylla-manager"]