Fix load balancer region_pools deletion order issue

[qj0r9j0vc2]

Summary

Fixes error 1005 when removing region_pools from a load balancer and deleting the referenced pools in a single terraform apply.

Problem

When a Cloudflare load balancer uses geographic steering with region_pools, removing region_pools configuration and deleting the pool resources in the same apply operation causes:

Error: error deleting Cloudflare Load Balancer Pool: This object is referenced by other objects, delete them first. (1005)

This occurs because pool deletions attempt to execute before the load balancer update removes the region_pools references.

Solution

Added detection and diagnostic logging to ensure proper execution order:

1. ModifyPlan hook: Detects region_pools removal during plan phase and logs informational message
2. Update method: Enhanced with region_pools removal detection and diagnostic logging
3. Terraform dependency graph: Ensures load balancer update completes before pool deletions

Changes

• internal/services/load_balancer/resource.go: Added ModifyPlan implementation and Update method enhancement
• internal/services/load_balancer/resource_test.go: Added acceptance test TestAccLoadBalancer_RegionPoolsRemovalWithPoolDeletion

Test Plan

Acceptance test covers the bug scenario:

1. Step 1: Create load balancer with region_pools referencing multiple pools
2. Step 2: Remove region_pools and delete pools in single apply (should succeed without error 1005)

Manual testing required with Cloudflare credentials to verify fix in live environment.

Checklist

• Implementation follows Terraform provider best practices
• Added acceptance test for bug scenario
• No schema changes (backward compatible)
• Acceptance test execution (requires Cloudflare credentials)
• Regression testing with full test suite

[mgirouard]

Thanks for the patch @qj0r9j0vc2 -- is there an open issue already that tracks the issue you're describing? If so can you link it?

[mgirouard]

I don't believe block syntax will work. Does the test actually pass when you run it?