Remove wget + rpm workaround to manage repos install in CentOS

RDO has moved rdo-release packages to a new infra which supports EMS so
we do not need to wget it and install it using local rpm install.

This partially reverts [1].

[1] https://review.opendev.org/c/openstack/devstack/+/884277/

Change-Id: I189d0c3da0e7b017e2568022c14e6c8fb28251f1
diff --git a/stack.sh b/stack.sh
index ad88eab..b03c3cd 100755
--- a/stack.sh
+++ b/stack.sh
@@ -311,22 +311,14 @@
             sudo dnf -y install https://rdoproject.org/repos/openstack-${rdo_release}/rdo-release-${rdo_release}.el8.rpm
         fi
     elif [[ $DISTRO == "rhel9" ]]; then
-        install_package wget
-        # We need to download rdo-release package using wget as installing with dnf from repo.fedoraproject.org fails in
-        # FIPS enabled systems after https://bugzilla.redhat.com/show_bug.cgi?id=2157951
-        # Until we can pull rdo-release from a server which supports EMS, this workaround is doing wget, which does
-        # not relies on openssl but on gnutls, and then install it locally using rpm
-        TEMPRDODIR=$(mktemp -d)
         if [[ "$TARGET_BRANCH" == "master" ]]; then
             # rdo-release.el9.rpm points to latest RDO release, use that for master
-            wget -P $TEMPRDODIR  https://rdoproject.org/repos/rdo-release.el9.rpm
+            sudo dnf -y install https://rdoproject.org/repos/rdo-release.el9.rpm
         else
             # For stable branches use corresponding release rpm
             rdo_release=$(echo $TARGET_BRANCH | sed "s|stable/||g")
-            wget -P $TEMPRDODIR https://rdoproject.org/repos/openstack-${rdo_release}/rdo-release-${rdo_release}.el9.rpm
+            sudo dnf -y install https://rdoproject.org/repos/openstack-${rdo_release}/rdo-release-${rdo_release}.el9.rpm
         fi
-        sudo rpm -ivh $TEMPRDODIR/rdo-release*rpm
-        rm -rf $TEMPRDODIR
     fi
     sudo dnf -y update
 }