Update SSM GPG key for ECS Anywhere install

[danehlim]

Summary

This adds the latest SSM public key to the aggregate key file for ECS Anywhere SSM Agent installation.

Previous similar pull request here: #3875

Implementation details

See "Summary" section above.

Testing

Manually followed steps to verify the signature of SSM Agent documented here: https://docs.aws.amazon.com/systems-manager/latest/userguide/verify-agent-signature.html

$ gpg --import amazon-ssm-agent.gpg
gpg: key 693ECA21: public key "SSM Agent <ssm-agent-signer@amazon.com>" imported
gpg: key 56BAA549: public key "SSM Agent <ssm-agent-signer@amazon.com>" imported
gpg: key 97DD04ED: public key "SSM Agent <ssm-agent-signer@amazon.com>" imported
gpg: key D0052E5D: public key "SSM Agent <ssm-agent-signer@amazon.com>" imported
gpg: Total number processed: 4
gpg:               imported: 4  (RSA: 4)
gpg: no ultimately trusted keys found

$ gpg --fingerprint D0052E5D
pub   4096R/D0052E5D 2025-01-22 [expires: 2026-07-15]
      Key fingerprint = 4855 A9E6 8332 16D6 A77D  8FE4 51A8 E050 D005 2E5D
uid                  SSM Agent <ssm-agent-signer@amazon.com>

$ curl -o /home/ec2-user/amazon-ssm-agent.rpm.sig https://s3.us-west-2.amazonaws.com/amazon-ssm-us-west-2/latest/linux_amd64/amazon-ssm-agent.rpm.sig

$ curl -o /home/ec2-user/amazon-ssm-agent.rpm https://s3.us-west-2.amazonaws.com/amazon-ssm-us-west-2/latest/linux_amd64/amazon-ssm-agent.rpm

$ gpg --verify amazon-ssm-agent.rpm.sig amazon-ssm-agent.rpm
gpg: Signature made Fri 10 Jan 2025 01:54:18 AM UTC using RSA key ID 97DD04ED
gpg: Good signature from "SSM Agent <ssm-agent-signer@amazon.com>"

New tests cover the changes: no

NOTE: Linux / Linux unit tests Github action for this pull request is currently failing for a reason unrelated to the changes in this pull request. The failing unit tests will be addressed separately in another commit/pull request.

Description for the changelog

Update SSM GPG key for ECS Anywhere install

Additional Information

Does this PR include breaking model changes? If so, Have you added transformation functions?

No

Does this PR include the addition of new environment variables in the README?

No

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.