Terraform AWS provider v6: aws_eip vpc, aws_instance cpu_core_count, data.aws_region name removed or renamed

Upgrade to the latest 5.x first and clear all deprecation warnings, then:

# aws_eip: before
resource "aws_eip" "x" { vpc = true }
# after
resource "aws_eip" "x" { domain = "vpc" }

# aws_instance: before
cpu_core_count       = 2
cpu_threads_per_core = 1
# after
cpu_options {
  core_count       = 2
  threads_per_core = 1
}

# data.aws_region: before
data.aws_region.current.name
# after
data.aws_region.current.region

# aws_s3_bucket (resource and data source): the bucket's own region attribute
# is now bucket_region; `region` is the Enhanced Region Support argument

Other removals: aws_eks_addon.resolve_conflicts (use resolve_conflicts_on_create / _on_update), provider endpoints.opsworks, endpoints.simpledb/sdb, endpoints.worklink. aws_instance.user_data is no longer hashed in state and is stored in clear text, so do not put secrets in it. Pin version = "~> 6.0" (or ~> 5.0 until migrated).