chore(serverbackup): switch to new SDK structure

[GokceGK]

Description

relates to STACKITTPR-574

Checklist

• Issue was linked above
• Code format was applied: make fmt
• Examples were added / adjusted (see examples/ directory)
• Docs are up-to-date: make generate-docs (will be checked by CI)
• Unit tests got implemented or updated
• Acceptance tests got implemented or updated (see e.g. here)
• Unit tests are passing: make test (will be checked by CI)
• No linter issues: make lint (will be checked by CI)

[github-actions]

Merging this branch will not change overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/enable	8.33% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule	14.33% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/utils	75.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/enable/datasource.go	14.58% (ø)	48	7	41
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/enable/resource.go	5.83% (ø)	120	7	113
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule/resource.go	13.89% (ø)	252	35	217
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule/schedule_datasource.go	0.00% (ø)	41	0	41
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule/schedules_datasource.go	26.79% (ø)	56	15	41
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/utils/util.go	75.00% (ø)	8	6	2

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/enable/datasource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/enable/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/schedule/schedules_datasource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/serverbackup_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverbackup/utils/util_test.go

[cgoetz-inovex]

Error message does not match check.

Also not sure if we should just remove this check. API docs sadly only specify integer for schedule.Id but not what valid values are, so I'd accept 0 here as valid. The old implementation would have accepted 0.

[GokceGK]

yes, you are right. I think I will remove this check.