Allow for custom_iam_policy_arns that are unknown during terraform apply

### Describe the Bug

Getting below mentioned error:

╷
│ Error: Invalid for_each argument
│
│ on .terraform\modules\data_science_lambda.data_science_lambda\iam-role.tf line 89, in resource "aws_iam_role_policy_attachment" "custom":
│ 89: for_each = local.enabled ? local.custom_iam_policy_arns_map : {}
│ ├────────────────
│ │ local.custom_iam_policy_arns_map will be known only after apply
│ │ local.enabled is true
│
│ The "for_each" map includes keys derived from resource attributes that
│ cannot be determined until apply, and so Terraform cannot determine the
│ full set of keys that will identify the instances of this resource.
│
│ When working with unknown values in for_each, it's better to define the map
│ keys statically in your configuration and place apply-time results only in
│ the map values.
│
│ Alternatively, you could use the -target planning option to first apply
│ only the resources that the for_each value depends on, and then apply a
│ second time to fully converge.
╵

=====================================================

### Expected Behavior

Policy should be created and alingned with Lambda role at runtime along with AWS Lambda function

### Steps to Reproduce

Sample Code:

locals {
enabled = module.this.enabled
custom_iam_policy_arns = [ aws_iam_policy.custom_s3_policy.arn ]
s3_lambda_environment = var.abc_lambda_env == null ? null : { variables = var.abc_lambda_env }
}

data "aws_iam_policy_document" "custom_s3_policy" {
version = "2012-10-17"

statement {
actions = [
"s3:ListBucket"
]
resources = [
"arn:aws:s3:::${data.terraform_remote_state.abc_bucket_id.outputs.bucket_id}"
]
}

statement {
actions = [
"secretsmanager:DescribeSecret",
"secretsmanager:GetSecretValue",
"secretsmanager:ListSecrets",
"secretsmanager:ListSecretVersionIds"
]
resources = [
"*"
]
}
}

resource "aws_iam_policy" "custom_s3_policy" {
name = "${module.this.id}-access-policy"
description = "Custom policy to allow access to one S3 bucket only."
policy = data.aws_iam_policy_document.custom_s3_policy.json
tags = module.this.tags
}

data "terraform_remote_state" "abc_bucket_id" {
backend = "s3"

config = {
bucket = var.abc_tfstate_bucket_name
key = var.abc_s3_bucket_key
region = "XXX"
}
}

module "abc_lambda" {
source = "cloudposse/lambda-function/aws"
version = "0.5.5"

enabled = true
function_name = "${module.this.id}"
description = "Lambda test."
s3_bucket = var.s3_lambda_s3_bucket
s3_key = var.s3_lambda_s3_key
runtime = var.s3_lambda_runtime
handler = var.s3_lambda_handler
lambda_environment = local.s3_lambda_environment
architectures = ["x86_64"]
memory_size = var.s3_lambda_memory_size
ephemeral_storage_size = var.s3_lambda_storage_size
timeout = var.s3_lambda_timeout
custom_iam_policy_arns = local.custom_iam_policy_arns
context = module.this.context
vpc_config = var.abc_lambda_vpc_config
}

resource "aws_lambda_permission" "allow_s3" {
statement_id = "AllowExecutionFromS3"
action = "lambda:InvokeFunction"
function_name = module.abc_lambda.function_name
principal = "s3.amazonaws.com"
source_arn = data.terraform_remote_state.abc_bucket_id.outputs.bucket_arn
}

### Screenshots

_No response_

### Environment

_No response_

### Additional Context

_No response_

Bắt đầu với resource được tạo aws_iam_role_policy_attachment.custom trong iam-role.tf ở dòng 89 và kiểm tra cách local.custom_iam_policy_arns_map được sử dụng trong for_each. Tái hiện cấu hình mẫu, sau đó xác minh rằng plan và apply có thể xử lý một policy ARN chỉ khả dụng tại thời điểm apply và tạo policy attachment cùng với Lambda role.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.