feat: Add support for `ipv6_ipam_pool_id`

[nshenry03]

Description

Add support for passing ipv6_ipam_pool_id and assign_generated_ipv6_cidr_block arguments to the aws_vpc resource.

Motivation and Context

I have a VPC where I need to pass the ipv6_ipam_pool_id and I couldn't do that without adding this feature.

Breaking Changes

None, the module works the same as it does today.

How Has This Been Tested?

• [ ] I have updated at least one of the examples/* to demonstrate and validate my change(s); I did not update any of the examples to test the new feature because BYOIPv6 is difficult to setup / test in a development environment.
• [x] I have tested and validated these changes using one or more of the provided examples/* projects; existing examples work as they did before if you don't pass in the new argument: ipv6_ipam_pool_id
• [x] I used the module for my own VPC and used the new argument ipv6_ipam_pool_id and it worked as expected.
• [x] I have executed pre-commit run -a on my pull request

[nshenry03]

Hey @antonbabenko , do you need anything more from me for this pull request? Thanks!

[nshenry03]

Okay @antonbabenko , I've made the suggested changes and things should be good to go now. Thanks!

[github-actions[bot]]

This PR has been automatically marked as stale because it has been open 30 days with no activity. Remove stale label or comment or this PR will be closed in 10 days

[github-actions[bot]]

This PR was automatically closed because of stale in 10 days

[github-actions[bot]]

I'm going to lock this pull request because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues. If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.