Remove use of suppress.CaseDifferenceV2Only

[danielrbradley]

This is split between 0004-fixup-Shared-features.patch and 0005-Modify-resources.patch.

History:

1. Originally introduced in Provider - Add the missing suppress.CaseDifference for case-insensitive string properties hashicorp/terraform-provider-azurerm#15182
2. Customised by Stack72
3. Removed in Refactor: Remove all usages of ThreePointOhBeta hashicorp/terraform-provider-azurerm#16812
4. Tweaked comment by JK

Function code:

// CaseDifferenceV2Only only suppress case difference for v2.0.
func CaseDifferenceV2Only(_, old, new string, _ *schema.ResourceData) bool {
	// FORK: Force attributes to maintain case-insensitivity to avoid breaking changes in Pulumi programs.
	return strings.EqualFold(old, new)
}

[danielrbradley]

Merged into #2051