Removes incorrect help text from EKS Kubernetes version field

What does this MR do?

Kubernetes version field for adding a new EKS cluster was using incorrect placeholder text. This MR removes that text.

Screenshots

Before	AfteR

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

Not needed

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers