fix: remove explicit aws_s3_bucket_acl (#815)

This resolves an issue related to the April 2023 S3 API changes. More
info can be found here:
hashicorp/terraform-provider-aws#28353

Closes #814

## Description

Remove the explicit private ACL that leads to an error during the apply
phase as with the new security defaults, it should no longer be needed.
I'm not 100% on the implications of removing this resource for existing
deployments, so if that's a concern we can go the route of adding the
explicit `aws_s3_bucket_ownership_controls` resource as per the related
issue.

## Migrations required

NO

## Verification

- Solves the issue in #814 using the recommendations from:
hashicorp/terraform-provider-aws#28353
- manually tested and checked that the cache is still accessible

Author: Ryan Causey

Diff for: modules/cache/main.tf

@@ -38,12 +38,6 @@ resource "aws_s3_bucket" "build_cache" {
   force_destroy = true
 }
 
-resource "aws_s3_bucket_acl" "build_cache_acl" {
-  bucket = aws_s3_bucket.build_cache.id
-
-  acl = "private"
-}
-
 resource "aws_s3_bucket_versioning" "build_cache_versioning" {
   bucket = aws_s3_bucket.build_cache.id