feat(sources): update arn-templates

> ⚠️ This Pull Request updates daily and will overwrite **all** manual changes pushed to the branch

Updates the arn-templates source from upstream. See details in [workflow run].

[Workflow Run]: https://github.com/cdklabs/awscdk-service-spec/actions/runs/20498412292

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*Automatically created by projen via the "update-source-arn-templates" workflow*

Signed-off-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]