fix(ci): Do not copy extended attributes for darwin build

[jefchien]

Description of the issue

The MakeMacPkg job in the Build Test Artifacts workflow has started failing at the "Copy binary" step:
https://github.com/aws/amazon-cloudwatch-agent/actions/runs/33896579998/job/101133623806

cp: build/bin/darwin/amd64/.: unable to copy extended attributes to /tmp/.: Operation not permitted

On macOS, cp attempts to replicate the source directory's extended attributes onto the target directory (/tmp). The only difference between the previously passing run and this failure is that the GitHub macOS runner image was updated from 20260727.0256 to 20260829.0321 and now seems to deny the copy, which breaks the darwin package build.

Description of changes

Added the -X flag to the cp commands that copy the build output and pkg dependencies into /tmp.

$ man cp
...
     -X    Do not copy Extended Attributes (EAs) or resource forks.

License

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Tests

Ran the workflow against the branch
https://github.com/aws/amazon-cloudwatch-agent/actions/runs/34255505664/job/102166185058

Requirements

Before commiting your code, please do the following steps.

1. Run make fmt and make fmt-sh
2. Run make lint

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Integration Tests

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