fix(sbom): ref generation if serialNumber is empty when input is cyclonedx file

[DmitriyLewen]

Description

serialNumber field is optional: https://cyclonedx.org/docs/1.4/json/#serialNumber
Changed ref generation if serialNumber is empty when input is cyclonedx file.

Related issues

• Close report error: unable to write results: failed to write results: CycloneDX marshal error: "": invalid bomLink format error #2998

Checklist

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• I've added tests that prove my fix is effective or that my feature works.
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