fix: Add `primary_ipv6` parameter to self-managed-node-group

[jmtsi]

Description

The launch template config in self-managed-node-group didn't include the parameter to set primary_ipv6, so I add it here. This has already been implemented for eks-managed-node-group in this PR

Motivation and Context

This parameter is needed to enable Assign primary IPv6 IP for self-managed-node-group nodes. This is required to make it possible to use instance-type targets when using IPv6 and AWS Load Balancer Controller

Breaking Changes

Simple addition, no breaking changes

How Has This Been Tested?

• [ ] I have updated at least one of the examples/* to demonstrate and validate my change(s)
• [x] I have tested and validated these changes using one or more of the provided examples/* projects
• [x] I have executed pre-commit run -a on my pull request

[antonbabenko]

This PR is included in version 20.24.3 :tada:

[jmtsi]

Wow, thanks for the quick reaction to my PR!

[github-actions[bot]]

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