Ensure IAM policies that allow full administrative privileges are not created and attached inline to a role

It is recommended and considered a standard security advice to grant least privileges that is, granting only the permissions required to perform a task. IAM policies are the means by which privileges are granted to users, groups, or roles. Determine what users need to do and then craft policies for them that let the users perform only those tasks, instead of granting full administrative privileges.

In AWS Console -

1. Sign in to the AWS Console and open the IAM Console.
2. Under Access Management, select Roles.
3. Choose the role you wish to edit.
4. Under Permissions policies, expand the policy you wish to edit using the + symbol.
5. Select Edit and configure the policy accordingly.
6. Select Review policy, then Save.

In Terraform -

1. In the aws_iam_role resource, update the assume_role_policy field accordingly.

References:
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_role