Build fails due to Node.js version incompatibility

[intagliated]

Description

The documentation build process fails when running yarn install due to a Node.js version incompatibility. The error occurs both in local builds and in the repository's CI/CD pipelines. This was after the version update mentioned in #817

Reproduction Steps

1. Clone the repository
2. Attempt to build documentation (or run the CI workflow)
3. Observe the Yarn installation failure

Affected CI Run

This issue is already visible in the repository's own CI:

• Workflow run: https://github.com/intagliated/opacus/actions/runs/25860259042
• Job: Install dependencies
• Status: Failed with exit code 1

Additional Context

• The current CI uses Node.js 20 actions (actions/checkout@v3)
• GitHub has deprecated Node.js 20 actions and will force Node.js 24 as default starting June 2nd, 2026
• Node.js 20 will be completely removed from runners on September 16th, 2026
• The problematic dependency requires Node.js 22.18.0+ or 24.11.0+

Impact

This prevents:

• Successful documentation builds
• CI/CD pipelines from passing
• Contributors from building the documentation locally

[intagliated]

[HuanyuZhang]

Fixed by #822.