bump deps

[fulldecent]

No description provided.

[Copilot]

Pull request overview

This PR updates the project’s tooling/runtime baselines and CI/dev-environment setup to align with newer Node/Yarn and Ruby versions, along with refreshing JavaScript dev dependencies and lockfile.

Changes:

• Bump JavaScript tooling dependencies (Prettier, html-validate, markdownlint-cli2, etc.) and regenerate yarn.lock.
• Standardize Ruby version via a checked-in .ruby-version and update docs/CI/devcontainer to use it.
• Update GitHub Actions workflows (new major versions of actions and explicit Corepack/Yarn activation) and set Node version via .nvmrc.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
yarn.lock	Regenerated lockfile reflecting updated dependency graph and Yarn lock metadata version.
package.json	Bumps dev tooling versions and updates packageManager to Yarn 4.18.0.
README.md	Updates local setup instructions to reference .ruby-version and adds guidance for keeping it in sync with GitHub Pages.
.ruby-version	Pins Ruby version for CI/devcontainer/local tooling consistency.
.nvmrc	Pins Node version used by CI and local tooling.
.github/workflows/code-lint.yml	Updates actions versions and ensures Corepack/Yarn activation before installs/lint.
.github/workflows/build-test-deploy.yml	Updates actions versions, reads Ruby version from .ruby-version, and ensures Corepack/Yarn activation.
.devcontainer/devcontainer.json	Switches devcontainer features to rbenv/nvm-based versioning and installs Ruby/Node/Yarn accordingly in postCreateCommand.

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