Add missing Dependabot labels to create-labels workflow

[Copilot]

Description

The create-labels.yaml workflow was missing label definitions that Dependabot references in dependabot.yml, causing PRs to fail when applying labels.

Changes:

• Added dependencies label (color: #0366d6) to workflow
• Added dotnet label (color: #512bd4) to workflow

Both labels now align with the Dependabot configuration across all five package ecosystems (root, src, tests, benchmarks, examples).

Type of change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Refactor

How Has This Been Tested?

• YAML syntax validation for both create-labels.yaml and dependabot.yml
• CodeQL security scan (0 alerts)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Screenshots (if applicable)

N/A

Additional context

This PR addresses feedback from PR #27. The workflow can be manually triggered via workflow_dispatch to create labels in the repository.

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