fix: disable repositories second time to downgrade kernel

It has been observed the image built with custom repositories will
contain the latest kernel and will not downgrade to match what is
contained within the custom repositories. By disabling the repositories
after installing `Minimal Install` it should then trigger a downgrade.

Signed-off-by: Jack Hodgkiss <jack@stackhpc.com>

Author: jackhodgkiss

elements/rocky-container-stackhpc/containerfiles/9-stackhpc

@@ -18,6 +18,15 @@ RUN if [[ ${ROCKY_USE_CUSTOM_DNF_MIRRORS} != "false" ]]; then \
 RUN dnf group install -y 'Minimal Install' --allowerasing && \
     dnf install -y findutils util-linux cloud-init
 
+# Repositories need to be disabled a second time to downgrade kernel.
+RUN if [[ ${ROCKY_USE_CUSTOM_DNF_MIRRORS} != "false" ]]; then \
+      dnf config-manager --disable \* && \
+      for REPO_URL in $(echo ${ROCKY_CUSTOM_DNF_MIRROR_URLS} | sed 's/,/ /g'); do \
+        dnf config-manager --add-repo ${REPO_URL}; \
+      done && \
+      dnf --allowerasing -y distro-sync; \
+    fi
+
 COPY <<EOF /etc/cloud/cloud.cfg.d/10-NetworkManager.cfg
 ---
 system_info: