rpm.sh might fail to find postgresql package even if it exists

[onurctirtir]

https://github.com/citusdata/packaging/blob/gh-pages/enterprise/rpm.sh#L47..L48

Here we execute yum info to check if postgresql package is available on pgdg repo.
yum info might sometimes ask for user input to install GPG key for pgdg repo.
However, since we redirect all the output to /dev/null, users might see such false errors:

PGDG repositories don't have postgresql13-server package for your operating system
Cannot install Citus, exiting.

This is because, yum info expects user to provide 'y' to install GPG key, but we don't already show that to users.

To reproduce, simply run rpm.sh on centos7.9 docker image.

[hanefi]

We can consider passing -y or --assume-yes option to yum info.

   -y, --assumeyes
          Automatically answer yes for all questions.

   List options are comma-separated. Command-line options override
   respective settings from configuration files.

https://man7.org/linux/man-pages/man8/yum.8.html