chore: remove terraform.tfstate.backup if it exists

[skip ci]

Author: php-coder

.github/workflows/provision-by-terraform.yml

@@ -106,7 +106,7 @@ jobs:
         if: always()
         working-directory: infra/terraform
         run: |
-          for FILE in vault-pass.txt terraform-data/terraform.tfplan terraform-data/terraform.tfstate terraform-data/terraform.tfvars; do
+          for FILE in vault-pass.txt terraform-data/terraform.tfplan terraform-data/terraform.tfstate terraform-data/terraform.tfstate.backup terraform-data/terraform.tfvars; do
             [ ! -f "$FILE" ] || rm -fv "$FILE"
           done
           [ ! -d terraform-data ] || git worktree remove terraform-data