Install jq before releasing. (#848)

- `jq` is now needed to run the script `modify_spec.sh`
- Since the release runs from the `docker.io/library/golang:1.22` image, it doesn't have jq installed
- as a workaround, the release script now installs jq first

.buildkite/release.sh

@@ -7,5 +7,9 @@ echo -n "$GPG_PRIVATE_SECRET" | base64 --decode | gpg --import --batch --yes --p
 echo "--- Caching GPG passphrase"
 echo "$GPG_PASSPHRASE_SECRET" | gpg --armor --detach-sign --passphrase-fd 0 --pinentry-mode loopback
 
+echo "--- Installing jq"
+apt-get update
+apt-get install jq -y
+
 echo "--- Release the binaries"
 make release