fix(runners): fix type mismatch in pool role conditional

[Brend-Smits]

Problem

The conditional for the runner role in modules/runners/pool.tf (introduced in #4875) returns inconsistent types:

role = var.iam_overrides["override_runner_role"] ? { arn = var.iam_overrides["runner_role_arn"] } : aws_iam_role.runner[0]

• True branch: { arn = "..." } (1 attribute)
• False branch: aws_iam_role.runner[0] (16 attributes including assume_role_policy, name, etc.)

Terraform requires both branches of a conditional to have consistent types. This causes a type error at plan time when override_runner_role = false (the default).

Fix

Move the conditional inside the object so both branches produce a string:

role = { arn = var.iam_overrides["override_runner_role"] ? var.iam_overrides["runner_role_arn"] : aws_iam_role.runner[0].arn }

This is consistent with how scale-up.tf (line 123) already handles the same conditional.

Testing

• Verified terraform plan succeeds with override_runner_role = false (default)
• The pool module's variable type is object({ arn = string }), so only the .arn attribute is needed

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

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