Raise minimum Node version to 20 and install Node 24 in setup scripts

[Copilot]

Bumps the declared minimum Node engine for the test packages and switches the dependency setup scripts to install Node.js 24 instead of relying on the distro npm package (Node 20 on Azure Linux 3.0).

Packages

• tests/npm-app and tests/js-interpreter-reuse: engines.node >=14 → >=20.

Setup scripts

• scripts/setup-ci.sh and scripts/setup-dev.sh: new install_node() downloads node-v24.17.0-linux-x64.tar.gz from nodejs.org, verifies its SHA256, extracts to /opt/node, and symlinks node/npm/npx into /usr/local/bin.
• Dropped the npm tdnf package from both scripts so the pinned Node 24 is the only one on PATH.

NODE_VERSION="v24.17.0"
NODE_SHA256="e0472427aa791ad80bdc426ff7cc73cdd28ed0f616d1ff9689a23a7f47f1265f"

install_node() {
    local archive="node-${NODE_VERSION}-linux-x64.tar.gz"
    curl -L --output "$archive" "https://nodejs.org/dist/${NODE_VERSION}/${archive}" || return 1
    echo "${NODE_SHA256}  ${archive}" | sha256sum --check --status || return 1
    rm -rf /opt/node && mkdir -p /opt/node &&
    tar -xzf "$archive" -C /opt/node --strip-components=1 &&
    ln -sf /opt/node/bin/{node,npm,npx} /usr/local/bin/
}

Notes

• js/ccf-app has no engines constraint and is left unchanged; the published @microsoft/ccf-app package is unaffected.
• Node version and checksum are pinned together; bumping the version requires updating NODE_SHA256 from the matching SHASUMS256.txt.

[Copilot]

Pull request overview

This PR updates the JavaScript test packages to require a newer Node.js baseline and makes the CI/dev setup scripts install a pinned Node.js release directly (rather than relying on the distro npm package), aligning the runtime used in CI/dev with the new minimum.

Changes:

• Raise engines.node in tests/npm-app and tests/js-interpreter-reuse from >=14 to >=20.
• Add Node.js install logic to scripts/setup-ci.sh and scripts/setup-dev.sh which downloads a pinned Node v24 tarball, verifies SHA256, installs to /opt/node, and symlinks into /usr/local/bin.
• Remove npm from the dependency install lists in both setup scripts.

Custom instructions used:

• .github/copilot-instructions.md
• .github/instructions/reviewing.instructions.md

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tests/npm-app/package.json	Bumps Node engine requirement for the npm-app test bundle.
tests/js-interpreter-reuse/package.json	Bumps Node engine requirement for the interpreter reuse test package.
scripts/setup-dev.sh	Installs a pinned Node.js version (v24) from nodejs.org and removes reliance on distro npm.
scripts/setup-ci.sh	Installs a pinned Node.js version (v24) during CI dependency setup and removes distro npm.

[maxtropets]

What is curl for? Don't see it used in this PR.