Add copyright header for sbom_generation.yaml file

[younesAmin]

Description

Add copyright header for sbom_generation.yaml file and Remove build_spec.yaml as it is replaced by sbom_generation.yaml

Motivation

The copyright header is necessary for the sbom_generation because it is an oracle own code The build_spec.yaml file is not used by Github Compliance Audit Service anymore and should be removed

[Craigacp]

Shouldn't this have a license header on it like the build spec used to?

[spavlusieva]

@Craigacp could you please merge if everything looks good to you?