add missing csp-nonce in sponsored benefits layout

[RyanEddyIC]

PR Checklist

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• Tests for the changes have been added (for bug fixes/features), and they use let helpers and before blocks.
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PR Type

What kind of change does this PR introduce?:

• Bugfix
• Feature (requires Feature flag)
• Data fix, Migration, or Report (inert code, no impact until run)
• Refactoring (no functional changes, no API changes)
• Build related changes
• CI related changes
• Dependency updates (e.g., add a new gem or update to a version)

What is the ticket # detailing the issue?

Ticket:

A brief description of the changes:

Current behavior:

New behavior:

Feature Flag

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Variable name:

• DC
• ME

Additional Context

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