ci(security): run cargo deny for licenses and duplicate dependencies

[dezzy-music]

Description

Adds deny.toml configuration for cargo-deny to check and enforce licensing policies (allowing MIT, Apache-2.0, BSD variants, ISC, Unicode, Unlicense, Zlib, BSL-1.0, CDLA-Permissive-2.0, CC0-1.0) and restrict dependencies to trusted crates.io registries. Integrates cargo deny check into the Dependency Audit workflow using EmbarkStudios/cargo-deny-action@v2.

Closes #163

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Tasks Completed

• Created deny.toml with allowed licenses, ban rules, and registry sources.
• Configured deny.toml in .github/workflows/audit.yml paths to trigger PR audits when updated.
• Added cargo-deny job executing cargo deny check via EmbarkStudios/cargo-deny-action@v2.
• Documented the change in PROGRESS.md.

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Acceptance Criteria

• deny.toml created allowing MIT, Apache-2.0, BSD, ISC, Unicode, etc.
• Dependency audit workflow updated with cargo deny check
• PROGRESS.md entry added, and the PR description includes Closes #163

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Stellar Address (Stellar Wave Program)

GDLCJGQLXZGDAAT5QGRF6FM2MBEER3FPYGCSVPXYL47G2ABIOX2M2S6K