provider: Remove now duplicate security issue link (#15282)
provider: Remove now duplicate security issue link (#15282)

The security policy (and issue template linking) is now automatically handled by the presence of an Organization-wide file: https://github.com/terraform-providers/.github/blob/master/SECURITY.md

This security policy is also present in the HashiCorp organization, for if/when the repository is transferred.
terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws