Add secrets to public repo for migrating LinkedIn publication pipeline from Travis CI to Github Actions

LinkedIn Pinot team is currently thinking of migrating the existing internal publication pipeline from travis CI to github actions, but it seems none of our LinkedIn committers/PMCs has the permission to add the secret key to the public repo. Could anyone who has "Admin" access help do that?

https://docs.github.com/en/free-pro-team@latest/actions/reference/encrypted-secrets#creating-encrypted-secrets-for-a-repository

Start by reading the linked GitHub encrypted-secrets documentation and confirming with the Pinot maintainers which secret and migration steps are required. Inspect the existing internal Travis CI publication pipeline if access is available; the work is done when the required repository secret is added and the GitHub Actions migration can authenticate successfully.

Written by the indexing model from the issue text.