v9.0.0 upgrade fails with "missing expected [" due to missing state migration for bot_management

## Description Upgrading from v8.x to v9.0.0 fails with `missing expected [` during `terraform plan`. The breaking change in v9.0.0 changed `product_enablement.bot_management` from boolean to Block List, but no `StateUpgraders` was provided to migrate existing state. ## Steps to reproduce 1. Have a `fastly_service_vcl` resource with `product_enablement` managed by v8.x 2. Upgrade provider to v9.0.0 3. Run `terraform plan` ## Error ``` Error: missing expected [ with module.fastly_service.fastly_service_vcl.this, on ../modules/fastly_service/main.tf line 16, in resource "fastly_service_vcl" "this": 16: resource "fastly_service_vcl" "this" { ``` On Terraform Cloud, `terraform plan` itself succeeds (0 changes), but plan JSON generation fails: ``` Failed to marshal plan to json: error marshaling prior state: missing expected [ ``` ## Cause Existing state (created by v8.x) has `bot_management` as a boolean: ```json "product_enablement": [ { "bot_management": false, "brotli_compression": true, "ddos_protection": [], "ngwaf": [], "origin_inspector": true, ... } ] ``` v9.0.0 expects `bot_management` as a Block List (`[]`), not a boolean (`false`). ## Expected behavior The provider should include a `StateUpgrader` to migrate `bot_management` from boolean to Block List format when upgrading from v8.x to v9.0.0. ## Versions - Terraform: v1.10.4 - Provider: v9.0.0 (upgraded from v8.x)