CI: Add rpm-build and rpmdevtools to Rocky8 image

Install rpm-build and rpmdevtools in the Rocky 8 build image, which can
be used to build RPM package in the future Rocky 8 scheduled CI
workflow.
diff --git a/devops/deploy/docker/build/rocky8/Dockerfile b/devops/deploy/docker/build/rocky8/Dockerfile
index 320a360..45d6706 100644
--- a/devops/deploy/docker/build/rocky8/Dockerfile
+++ b/devops/deploy/docker/build/rocky8/Dockerfile
@@ -131,6 +131,8 @@
         util-linux-ng \
         wget \
         which \
+        rpm-build \
+        rpmdevtools \
         zlib-devel && \
     dnf install -y -d0 --enablerepo=devel \
         liburing-devel \