OSS issue in "Developing Logstash Core"

#### Tell us about the issue

I was going through "Developing Logstash Core" section -> [https://github.com/elastic/logstash#developing-logstash-core](url).

When I ran the command `bin/logstash -e 'input { stdin { } } output { stdout {} }'`,
I got the error as:
`An unexpected error occurred! {:error=># [https://discuss.elastic.co/t/installation-error/358588](url), and I got pointed to an existing issue, #16025. When I changed `OSS` to `false` everything worked perfectly.

Should we remove the OSS step in the documentation?

**URL:**

https://github.com/elastic/logstash#developing-logstash-core

Start at the “Developing Logstash Core” section in the repository README and reproduce the documented `bin/logstash -e 'input { stdin { } } output { stdout {} }'` command with the OSS setting. Review existing issue #16025 and the linked forum discussion for the documented cause. Done means the OSS step and command are corrected or removed so the instructions work as intended.

Written by the indexing model from the issue text.