fix(deps): upgrade undici dependency to v6.23.0

[roggervalf]

There is a vulnerability detected in undici v5, recommendation is to migrate at least to v6.23.0 https://osv.dev/vulnerability/GHSA-g9mf-h72j-4rw9

[Copilot]

Pull request overview

This PR upgrades the undici dependency from v5.28.5 to v6.23.0 to address a security vulnerability (GHSA-g9mf-h72j-4rw9). The upgrade includes updating the ProxyAgent configuration to use the new v6 API for handling SSL certificate rejection.

Changes:

• Updated undici dependency from ^5.28.5 to ^6.23.0 in package.json
• Refactored SSL error handling to use the new requestTls configuration option in ProxyAgent constructor
• Removed the @fastify/busboy dependency (no longer required by undici v6)

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 3 comments.

File	Description
packages/http-client/package.json	Updated undici dependency version to ^6.23.0
packages/http-client/package-lock.json	Updated lock file with undici v6.23.0 and removed @fastify/busboy dependency
packages/http-client/src/index.ts	Refactored ProxyAgent SSL error handling to use requestTls configuration instead of post-construction property assignment

Files not reviewed (1)

• packages/http-client/package-lock.json: Language not supported

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[Copilot]

Undici v6 requires Node.js >=18.17, but the CI/CD tests run on Node.js 20.x and 24.x. While these versions satisfy the requirement, older GitHub Actions runners may use Node.js 16.x. Consider documenting this breaking change as it increases the minimum Node.js version requirement from v14 (undici v5) to v18.17 (undici v6).

[roggervalf]

it should be confirmes by maintainers as if node versiones below 18 are not listed in unit tests, it could be expected to not support them