fix: Use environment variable for Node.js version in echo command

[Mrtenz]

The "Print Node.js version" step interpolates the node version directly into the shell command via ${{ ... }}, which is a GitHub Actions expression injection anti-pattern.

This changes it to pass the value through an env variable instead, which is the recommended safe approach.

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Note

Low Risk
Logging-only change with no behavior or security surface beyond avoiding expression injection in one echo step.

Overview
The Print Node.js version step no longer embeds ${{ steps.setup-node.outputs.node-version }} in the run script. It sets NODE_VERSION in env and echoes $NODE_VERSION in bash, matching GitHub’s guidance to avoid expression injection in shell steps.

Logged output is unchanged; only how the version is passed into the shell differs.

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