duplicate entries on each reapply

[cloudlady911]

Describe the bug
I am trying to create variables in my Octo projects

Steps to reproduce

1. Create definition in octopus.tf

## efs sg to PSR IAC Project
resource "octopusdeploy_variable" "efs-sg" {
  owner_id  = "Projects-383"
  type      = "String"
  name      = "Project.EFS.SG"
  value     = aws_security_group.efs_access_sg.id
}

2. Apply
3. Project.EFS.SG exists with correct security group id
4. Reapply
5. Previously created variable now has two identical values
6. Reapply
7. Same variable now has 3 identical values

Expected behavior
the system should realize that this is an unchanged item and not modify it.

logs:
`# octopusdeploy_variable.vpc_id will be created
November 2nd 2023 11:22:03Info

• resource "octopusdeploy_variable" "vpc_id" {
  November 2nd 2023 11:22:03Info
  • encrypted_value = (known after apply)
    November 2nd 2023 11:22:03Info
  • id = (known after apply)
    November 2nd 2023 11:22:03Info
  • is_editable = true
    November 2nd 2023 11:22:03Info
  • is_sensitive = false
    November 2nd 2023 11:22:03Info
  • key_fingerprint = (known after apply)
    November 2nd 2023 11:22:03Info
  • name = "Project.VPC.ID"
    November 2nd 2023 11:22:03Info
  • owner_id = "Projects-384"
    November 2nd 2023 11:22:03Info
  • space_id = (known after apply)
    November 2nd 2023 11:22:03Info
  • type = "String"
    November 2nd 2023 11:22:03Info
  • value = "vpc-032fd1fb0f598ee71"
    November 2nd 2023 11:22:03Info
    } `

Screenshots
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Environment and versions:

• OS: linux
• Octopus Server Version: 2023.2.12673
• Terraform Version: 1.6.2
• Octopus Terraform Provider Version: Terraform_Version=1.6.2

Additional context
Add any other context about the problem here.

[mjhilton]

Duplicates #212

There is more discussion and reproduction steps on the earlier issue #212, including a workaround which might help.