SUP-2919: Add ScalerManagedPolicyARNs parameter for Lambda execution role

[Mykematt]

Description

Checklist

• Tests pass locally
• Added tests for new features/fixes
• Updated documentation (if applicable)
• Linting checks pass

Release Notes

• New ScalerManagedPolicyARNs parameter
• Requires scaler release with ManagedPolicyARNs support

• My changes affect the public API (variable renames, new stack parameters, etc)
  • I have added a note at the top of the release notes highlighting the API changes
• Any changes to external libraries (agent, scaler function, etc) have been flagged in release notes

Dependencies

• Depends on PR#[274[](https://github.com/SUP-2919: Add ManagedPolicyARNs to Lambda Scaler buildkite-agent-scaler#274)

[mcncl]

@Mykematt this looks good, would you be able to rebase the PR so that changes from main are merged in and a new build is kicked off with the dependent changes in the agent scaler stack?

[Mykematt]

@Mykematt this looks good, would you be able to rebase the PR so that changes from main are merged in and a new build is kicked off with the dependent changes in the agent scaler stack?

Thanks @mcncl. Just getting back to this after my break. Rebase completed.

[mcncl]

@Mykematt looks like some failures in CI regarding missing stack keys?

[Mykematt]

@mcncl finally able to fix. CI test now passes.