ci: fail installing Helm if wget is unavailable

In case `wget` is not installed, downloading the Helm release will fail.
The `install-helm.sh` script won't return a fatal error in that case,
and CI jobs continue running in an environment that is not ready.

By adding a check that exist the script with a failure, the CI will now
correctly report a problem when Helm can not be downloaded.

See-also: #3430
Signed-off-by: Niels de Vos <ndevos@redhat.com>
(cherry picked from commit fa97875)

scripts/install-helm.sh

@@ -136,7 +136,7 @@ install() {
         mkdir -p ${TEMP}
         # shellcheck disable=SC2021
         dist=$(echo "${dist}" | tr "[A-Z]" "[a-z]")
-        wget "https://get.helm.sh/helm-${HELM_VERSION}-${dist}-${arch}.tar.gz" -O "${TEMP}/helm.tar.gz"
+        wget "https://get.helm.sh/helm-${HELM_VERSION}-${dist}-${arch}.tar.gz" -O "${TEMP}/helm.tar.gz" || exit 1
         tar -C "${TEMP}" -zxvf "${TEMP}/helm.tar.gz"
     fi
     echo "Helm install successful"