Update deploy_website.yml and docusaurus.config.js for Docusaurus compatibility

[Copilot]

Node 20 reaches end-of-life April 2026 and onBrokenMarkdownLinks is deprecated at the top level in Docusaurus 3.x. This updates the CI workflow and config to stay current.

Changes proposed in this pull request

• deploy_website.yml: Bump Node.js 20 → 22 (current LTS, supported through April 2027)
• docusaurus.config.js: Migrate deprecated top-level onBrokenMarkdownLinks to markdown.hooks.onBrokenMarkdownLinks (removed in v4)
• docusaurus.config.js: Remove duplicate /docs/changelog/2025-6-13-0 redirect entry that caused a build warning

Related issue(s)

Copilot generated summary

Copilot summary

Bumps the CI Node.js version from 20 to 22 to avoid running on a near-EOL runtime. Migrates the onBrokenMarkdownLinks option from the deprecated top-level config to markdown.hooks.onBrokenMarkdownLinks as required by Docusaurus 3.x ahead of v4 removal. Removes a duplicate redirect entry for /docs/changelog/2025-6-13-0 that produced a build warning.

To-Do

• Update documentation to reflect this changes
• Update changelog to reflect this changes

Contributing

By submitting this pull request, I confirm the following:

• I have read and understood the contributing guidelines and the code of conduct.
• I have have added my name, username or email to the contributors list or don't want to.
• The code or resource is compatible with the GNU General Public License v3.0.

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