Set pipefail in the update script

When download of the repository metadata fails or returns bogus
information pipes downstream will fail and the failure will get masked
which leads to bogus PRs like #4

update.sh

@@ -2,6 +2,7 @@
 #!nix-shell -i bash -p curl jq ripgrep gawk
 
 set -eux
+set -o pipefail
 
 readarray -t RELEASES <<<"$(curl https://api.github.com/repos/openhab/openhab-distro/tags | jq -r '.[].name' | rg '^\d+\.\d+\.\d+*$')"
 MOST_RECENT=${RELEASES[0]}