[fix] take first result on YB_RELEASE check

[jlisthood]

Before running ./install_software.sh 2024.1.3.0 would have multi-line values for YB_RELEASE, YB_PACKAGE_URL, and YB_PACKAGE_NAME:

YB_RELEASE: 2024.1.3.0-b105
2024.1.3.0-b105
2024.1.3.0-b105
YB_PACKAGE_URL: https://downloads.yugabyte.com/releases/2024.1.3.0/yugabyte-2024.1.3.0-b105
2024.1.3.0-b105
2024.1.3.0-b105-linux-x86_64.tar.gz
YB_PACKAGE_NAME: yugabyte-2024.1.3.0-b105
2024.1.3.0-b105
2024.1.3.0-b105-linux-x86_64.tar.gz

This would cause the install script to fail since YB_PACKAGE_URL is not valid. wget would fail to grab https://downloads.yugabyte.com/releases/2024.1.3.0/yugabyte-2024.1.3.0-b105 above.

By taking the first result using | head -n 1 the install script works fine:

YB_RELEASE: 2024.1.3.0-b105
YB_PACKAGE_URL: https://downloads.yugabyte.com/releases/2024.1.3.0/yugabyte-2024.1.3.0-b105-linux-x86_64.tar.gz
YB_PACKAGE_NAME: yugabyte-2024.1.3.0-b105-linux-x86_64.tar.gz

In this case, wget https://downloads.yugabyte.com/releases/2024.1.3.0/yugabyte-2024.1.3.0-b105-linux-x86_64.tar.gz ends up succeeding

I believe the root cause is that we see these 3 versions mentioned in release tags:

• 2024.1.3.0-b105
• 2024.1.3.0-b105-aarch64
• 2024.1.3.0-b105-x86_64

So the grep -Eo "2024.1.3.0-b[0-9]+" matches all 3 and returns 2024.1.3.0-b105 3 times.