fix: make PURLs use oci type / include architecture in --source-version

[dervoeti]

Same thing as stackabletech/actions#11, but for our operator images. It probably makes sense for the same person to review both this PR and the other.

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Use OCI type for PURLs, according to https://github.com/package-url/purl-spec/blob/master/PURL-TYPES.rst#oci

This is more correct in general and most importantly makes the PURL equal to the one Trivy generates for our container images.

Hint: To check the PURL Trivy generates, run for example these commands:

trivy image --scanners vuln -f cyclonedx -o airflow-result.cdx.json oci.stackable.tech/sdp/airflow-operator:0.0.0-dev-amd64
jq -r '.metadata.component.purl' airflow-result.cdx.json

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The second commit includes the architecture in the component version in the SBOM (0.0.0-dev-amd64 instead of 0.0.0-dev). That is in line with the image tag and we also do it this way with our product images.

[Techassi]

KGTM, but it I would highly recommend that we adjust the workflow to use our central actions instead of relying on these custom Makefile commands.

This can be tackled after the release of SDP 24.11 is done.