Add missing copyright headers

cmd/flux/check_test.go

cmd/flux/create_source_git_test.go

cmd/flux/helmrelease_test.go

cmd/flux/kustomization_test.go

cmd/flux/logs_test.go

cmd/flux/main_e2e_test.go

cmd/flux/main_test.go

cmd/flux/main_unit_test.go

cmd/flux/manifests.embed.go

internal/utils/apply.go

pkg/log/log.go

tests/azure/azure_test.go

tests/azure/terraform.go

tests/azure/util_test.go