Potential flaky test

Nobody has claimed this yet.

Saw this test failure in CI:
```
--- FAIL: TestLauncher_Pkger (3.93s)
--- FAIL: TestLauncher_Pkger/managing_pkg_lifecycle_with_stacks (1.98s)
--- FAIL: TestLauncher_Pkger/managing_pkg_lifecycle_with_stacks/apply_a_pkg_with_a_stack_and_associations (0.47s)
--- FAIL: TestLauncher_Pkger/managing_pkg_lifecycle_with_stacks/apply_a_pkg_with_a_stack_and_associations/should_unassociate_resources_from_label_when_removing_association_in_pkg (0.08s)
pkger_test.go:877:
Error Trace: pkger_test.go:704
pkger_test.go:804
pkger_test.go:877
Error: Received unexpected error:
resource_type="label_mapping" err="failed to apply resource"
metadata_name="telegrafs:069ba262537e2000:069ba26252790000" err_msg="Cannot add label, label already exists on resource"
Test: TestLauncher_Pkger/managing_pkg_lifecycle_with_stacks/apply_a_pkg_with_a_stack_and_associations/should_unassociate_resources_from_label_when_removing_association_in_pkg
--- FAIL: TestLauncher_Pkger/apply_a_template_of_all_new_resources (0.43s)
--- FAIL: TestLauncher_Pkger/apply_a_template_of_all_new_resources/pkg_with_same_bkt-var-label_does_nto_create_new_resources_for_them (0.19s)
pkger_test.go:3238:
Error Trace: pkger_test.go:3238
Error: Received unexpected error:
resource_type="label_mapping" err="failed to apply resource"
metadata_name="telegrafs:069ba2642bbe2000:069ba263f4390001" err_msg="Cannot add label, label already exists on resource"
Test: TestLauncher_Pkger/apply_a_template_of_all_new_resources/pkg_with_same_bkt-var-label_does_nto_create_new_resources_for_them
```
I couldn't reproduce it locally

Start with the failing subtests in pkger_test.go, including the cases around lines 877 and 3238, and review their setup for label_mapping resources. Reproduce the CI failures if possible; done means the tests pass reliably without unexpected duplicate-label errors.

Written by the indexing model from the issue text.