fix: Update aws_sns_topic_subscription endpoint to use qualified arn (#231)

This commit updates the `aws_sns_topic_subscription` resource to use the `lambda_function_qualified_arn` output for the `endpoint` value.

Also bump the `lambda` module to `6.8.0`, which is the latest version that maintains compatability with `aws` v4 provider.

Fixes: #230

Author: fatmcgav

README.md

@@ -76,7 +76,7 @@ See the [functions](https://github.com/terraform-aws-modules/terraform-aws-notif
 
 | Name | Source | Version |
 |------|--------|---------|
-| <a name="module_lambda"></a> [lambda](#module\_lambda) | terraform-aws-modules/lambda/aws | 3.2.0 |
+| <a name="module_lambda"></a> [lambda](#module\_lambda) | terraform-aws-modules/lambda/aws | 6.8.0 |
 
 ## Resources
 

main.tf

@@ -73,14 +73,14 @@ resource "aws_sns_topic_subscription" "sns_notify_slack" {
 
   topic_arn           = local.sns_topic_arn
   protocol            = "lambda"
-  endpoint            = module.lambda.lambda_function_arn
+  endpoint            = module.lambda.lambda_function_qualified_arn
   filter_policy       = var.subscription_filter_policy
   filter_policy_scope = var.subscription_filter_policy_scope
 }
 
 module "lambda" {
   source  = "terraform-aws-modules/lambda/aws"
-  version = "3.2.0"
+  version = "6.8.0"
 
   create = var.create