fix: [v8] Stale launch template version causing inconsistent final plan

[matttrach]

Release #1616 (main PR) in release/v8 for #730 (main issue)

[matttrach]

Cut release candidate for validation:
https://github.com/rancher/terraform-provider-rancher2/releases/tag/v8.1.0-rc1

[matttrach]

@krunalhinguu, please assign someone from your team to validate.