Update DNS entry to reflect new naming scheme

[jmorrowomni]

🗣 Description

Add CNAME entry for the Software Attestation team to point to new Landing Zone ALB.

💭 Motivation and context

Due to an External Affairs requirement, the original name can not be used. This updates both the CNAME record and the target.

🧪 Testing

DNS resolution will be verified after the record is created.

✅ Pre-approval checklist

• [X] This PR has an informative and human-readable title.
• [X] Changes are limited to a single goal - eschew scope creep!
• [x] All relevant type-of-change labels have been added.
• [X] I have read the CONTRIBUTING document.
• [X] These code changes follow cisagov code standards.
• [x] All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• [x] All new and existing tests pass.

[dav3r]

To test this, I applied it and it looks good to me. @jmorrowomni can you please confirm? Once you do, I will merge this PR.

[jmorrowomni]

To test this, I applied it and it looks good to me. @jmorrowomni can you please confirm? Once you do, I will merge this PR.

Looks good!