perf: Optimize SBOM validation by removing itertools.chain

[saquibsaifee]

Description

This pull request optimizes the Bom.validate performance by replacing itertools.chain and other complex generator expressions with list/set collections and iterations.

During the generation of large SBOMs, validation times were high due to generator evaluation.
With this change, the Bom.validate() running time on an SBOM with 2500 nested components and 2500 services executed 10 times drops from ~49.4 seconds down to ~5.1 seconds. This yields a ~10x execution speedup in terms of validation execution alone.

Changes:

• Added dependency caching to avoid evaluating components and dependencies that have already been validated.
• Removed unused generator usages mapped via map and itertools.chain for gathering dependency references and testing root component dependency trees.
• Flatted logic to iterate over all elements with list additions list.extend rather than dynamically generating generators at runtime.

AI Tool Disclosure

• My contribution does not include any AI-generated content
• My contribution includes AI-generated content, as disclosed below:
  • AI Tools: Gemini Jules
  • LLMs and versions: Gemini 3.1 Pro

Affirmation

• My code follows the CONTRIBUTING.md guidelines

[saquibsaifee]

During the generation of large SBOMs, validation times were high due to generator evaluation.
With this change, the Bom.validate() running time on an SBOM with 2500 nested components and 2500 services executed 10 times drops from ~49.4 seconds down to ~5.1 seconds. This yields a ~10x execution speedup in terms of validation execution alone.

[codacy-production]

Up to standards ✅

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[read-the-docs-community]

Documentation build overview

📚 CycloneDX Python Library | 🛠️ Build #34315145 | 📁 Comparing e05bb2f against latest (52cb3c9)

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2 files changed

± autoapi/cyclonedx/model/vulnerability/index.html
± autoapi/cyclonedx/contrib/vulnerability/cvss/index.html

[saquibsaifee]

@jkowalleck can you take a look at this PR to boost SBOM generation turn around