fix(deps): update module github.com/tmccombs/hcl2json to v0.6.8

mentioned in merge request common-ci-task-tests!359 (merged)

mentioned in merge request common-template-copier!479 (merged)

mentioned in merge request gitlab-com/gl-infra/gitlab-dedicated/library/ip-allowlist-deny-blackbox!276 (merged)

mentioned in merge request gitlab-com/gl-infra/gitlab-dedicated/library/terraform/resource-tagger!91 (merged)

mentioned in merge request gitlab-org/analytics-section/platform-insights/data-insights-platform-infra!66 (merged)

mentioned in merge request nolith/mise2nix!53 (merged)

mentioned in merge request gitlab-com/gl-infra/terraform-modules/cloudflare/zones!21 (merged)

mentioned in merge request gitlab-com/gl-infra/terraform-modules/cloudflare/dns!16 (merged)