[EKS] [request]: ability to add node labels with an empty value

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**Tell us about your request**

We would like Amazon EKS to support node labels with empty values. This would allow us to use node selectors such as `node-role.kubernetes.io/control-plane: ""`, which is a valid configuration in Kubernetes but currently not supported by EKS.

**Which service(s) is this request for?**

EKS (Elastic Kubernetes Service)

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**

In Kubernetes, it's valid to assign node labels with empty values, such as `node-role.kubernetes.io/control-plane: ""`. This practice is useful for certain node selection and scheduling strategies. However, when creating node groups in EKS, specifying labels with empty values is not permitted. This limitation prevents us from implementing our desired node selection mechanisms, complicating our infrastructure management and deployment processes.

**Are you currently working around this issue?**

**Additional context**

This issue is similar to the one discussed in [aws-sdk-go-v2 issue #2267](https://github.com/aws/aws-sdk-go-v2/issues/2267), where creating node groups with empty label values is not supported by EKS despite being valid in Kubernetes. Our interaction with EKS is managed through Pulumi, which abstracts some of the AWS SDK functionalities, but the limitation regarding empty label values persists.

**Attachments**

_No attachments at this time._

No repository files, tests, or implementation entry points are mentioned. Start by reviewing EKS node-group label validation and the linked aws-sdk-go-v2 issue #2267; done means EKS accepts node labels whose values are empty strings while preserving valid Kubernetes behavior.

Written by the indexing model from the issue text.