Feature/upgrade to golangci lint v2

[Manuelvaas]

Description

relates to #1277 and STACKITTPR-253

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	1.26% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/access_token	21.43% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/cdn/distribution	55.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/dns	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/image	36.75% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/logme/credential	10.65% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/logs	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/mariadb/credential	15.47% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/objectstorage/credential	21.78% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/credential	15.25% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/rabbitmq/credential	22.49% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/redis/credential	15.22% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/scf	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverupdate	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/ske	0.00% (ø)
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/testutil	39.83% (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/cdn/distribution/resource.go	50.70% (ø)	503	255	248
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/image/resource.go	31.23% (ø)	285	89	196
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/logme/credential/datasource.go	0.00% (ø)	39	0	39
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/logme/credential/resource.go	13.85% (ø)	130	18	112
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/mariadb/credential/datasource.go	0.00% (ø)	39	0	39
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/mariadb/credential/resource.go	19.72% (ø)	142	28	114
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/objectstorage/credential/datasource.go	23.29% (ø)	73	17	56
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/objectstorage/credential/resource.go	21.30% (ø)	230	49	181
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/credential/datasource.go	0.00% (ø)	39	0	39
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/opensearch/credential/resource.go	19.57% (ø)	138	27	111
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/rabbitmq/credential/datasource.go	0.00% (ø)	39	0	39
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/rabbitmq/credential/resource.go	27.65% (ø)	170	47	123
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/redis/credential/datasource.go	0.00% (ø)	39	0	39
github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/redis/credential/resource.go	19.31% (ø)	145	28	117
github.com/stackitcloud/terraform-provider-stackit/stackit/provider.go	1.26% (ø)	159	2	157

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/access_token/ephemeral_resource_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/dns/dns_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/iaas/iaas_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/logs/logs_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/scf/scf_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/serverupdate/serverupdate_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/ske/ske_acc_test.go
• github.com/stackitcloud/terraform-provider-stackit/stackit/internal/testutil/testutil_test.go