[BF-7150]: Fix Dependabot alerts (fast-xml-builder, ws, sigstore)

[ThomasTrepanier]

Summary

• BF-7150: removes the vulnerable fast-xml-builder dependency chain through supported AWS SDK updates.
• BF-7673: updates ws to a patched release.
• BF-7782: updates Yarn tooling so all sigstore paths use the patched release, with aligned CLI and Core peer versions.

Why

Resolve three high-severity dependency vulnerabilities while preferring supported upstream dependency paths and preserving a compatible Yarn build-tool dependency graph.

How was it tested

• Confirmed fast-xml-builder is absent, ws resolves to 7.5.13, and sigstore resolves to 4.1.1
• Confirmed Builder and CLI resolve Core 4.9.1
• yarn build
• yarn ts-check
• yarn test --runInBand (39 tests)

  

[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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