chore(release) fix iam role used for dry run releases DEVPROD-21408

[drichmdb]

This commit adjusts our release dry run task to use the correct IAM role for its operations. The non-dry-run release task was using the expected role, but dry-run wasn't assuming the role we need to use.

[Copilot]

Pull Request Overview

This PR fixes the IAM role configuration for dry run releases by ensuring the correct AWS role is assumed and credentials are properly set. The dry run release task was missing the IAM role assumption that the non-dry-run release task already had.

• Adds ec2.assume_role command to assume the required IAM role for dry run releases
• Sets up AWS credential environment variables for the download center artifacts

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
.evergreen/evergreen.yml.in	Template file updated with IAM role assumption and AWS credential environment variables for dry run releases
.evergreen.yml	Generated file updated with the same IAM role assumption and AWS credential environment variables

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[Copilot]

The IAM role ARN is hardcoded with a specific AWS account ID (119629040606). Consider using an environment variable or parameter to make this configurable across different environments and avoid exposing account details in the codebase.

[Copilot]

The IAM role ARN is hardcoded with a specific AWS account ID (119629040606). Consider using an environment variable or parameter to make this configurable across different environments and avoid exposing account details in the codebase.

[gagik]

blocking the merge before release, LGTM generally though