feat(ci): re-enable linting rule to prevent usage of deprecated code

[rubenhoenle]

Description

can be re-enabled now since the migration to the new SDK layer is done

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 increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion	56.72% (+4.04%)	👍
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer	64.15% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/project	45.59% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/utils	77.78% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/loadbalancer/loadbalancer	51.88% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/instance	25.83% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/resourcemanager/utils	75.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/sfs	0.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion/conversion.go	56.72% (+4.04%)	134 (+3)	76 (+7)	58 (-4)	👍
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/datasource.go	0.00% (ø)	43	0	43
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/resource.go	67.09% (ø)	939	630	309
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/project/datasource.go	45.59% (ø)	68	31	37
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/utils/util.go	77.78% (ø)	27	21	6
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/loadbalancer/loadbalancer/resource.go	55.59% (ø)	572	318	254
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/instance/resource.go	29.25% (ø)	318	93	225
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/resourcemanager/utils/util.go	75.00% (ø)	8 (-8)	6 (-6)	2 (-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/conversion/conversion_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/alb/applicationloadbalancer/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/project/datasource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/utils/util_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/loadbalancer/loadbalancer/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/instance/resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/opensearch_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/resourcemanager/utils/util_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/sfs/sfs_test.go