Does not support validating Enterprise SSO users

[lukasz-mitka]

Description Validation fails on checking valid enterprise sso users Example: @user-name-can-be-very-long_and-has-underscore

Validation fails after adding SSO user to CODEOWNERS file.

Expected result User should be validated successfully.

Actual result Fails with

Owner @user_id does not look like a GitHub username or team name

Steps to reproduce Add * @user_id to CODEOWNERS file

Troubleshooting Here's the regex that doesn't match it. https://github.com/mszostok/codeowners-validator/blob/84b4fa2742240c05af8c81185e91947d90222106/internal/check/valid_syntax.go#L16

[lukasz-mitka]

I just noticed I only fixed the _ part of this issue in #209. The unlimited username length will still be an issue :(

[lukasz-mitka]

@mszostok Could you please create a release with what we have already available?

Since this is a docker action I can't override the version in a reasonable manner. And I need #209 available.