fix: tf backend can't be a variable

.github/workflows/arrow-aws.yml

@@ -91,15 +91,16 @@ jobs:
       # Connects to remote state backend and download providers.
       - name: Terraform Init
         working-directory: ${{ env.TERRAFORM_DIRECTORY }}
-        run: terraform init
+        run: |
+          terraform init \
+            -backend-config="bucket=${{ secrets.TERRAFORM_STATE_BUCKET }}" \
+            -backend-config="key=arrow.tfstate"
 
       # Deploys infrastructure or changes to infrastructure.
       - name: Terraform Apply
         if: inputs.action == 'create'
         working-directory: ${{ env.TERRAFORM_DIRECTORY }}
         env:
-          TF_VAR_terraform_state_bucket: ${{ secrets.TERRAFORM_STATE_BUCKET }}
-          TF_VAR_terraform_state_key: arrow.tfstate
           TF_VAR_ec2_size: ${{ inputs.size }}
         run: |
           terraform apply \

hosts/arrow/aws/main.tf

@@ -1,7 +1,5 @@
 terraform {
   backend "s3" {
-    bucket         = var.terraform_state_bucket
-    key            = var.terraform_state_key
     region         = "us-east-1"
     dynamodb_table = "terraform-state-lock"
   }

hosts/arrow/aws/variables.tf

@@ -8,13 +8,3 @@ variable "images_bucket" {
   description = "Name of the bucket in which to store the NixOS VM images."
   type        = string
 }
-
-variable "terraform_state_bucket" {
-  description = "Name of the bucket in which to store the Terraform state information."
-  type        = string
-}
-
-variable "terraform_state_key" {
-  description = "Path of the file in which to store the Terraform state information."
-  type        = string
-}