Fixed comment form not showing when there are no system notes

What does this MR do and why?

Updated conditional to always show the create comment form on work items.

Screenshots or screen recordings

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. In rails console enable the okrs_mvc feature flag

   Feature.enable(:okrs_mvc)

2. Create an OKR in the issue list of a project.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #387663 (closed)