Fix syntax for reading package metadata in GitHub Actions workflow

[kasuken]

Correct the syntax for outputting package metadata in the GitHub Actions workflow to ensure proper variable assignment.

[Copilot]

Pull Request Overview

This PR fixes the syntax for reading package metadata in a GitHub Actions workflow to ensure proper variable assignment when outputting to $GITHUB_OUTPUT.

• Adds proper double quotes around $GITHUB_OUTPUT variable references
• Corrects the JavaScript expression for generating the VSIX filename to use string concatenation instead of template literals with console.log
• Ensures consistent shell variable handling throughout the workflow

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

The node -p command expects a single expression, but this code declares a variable const p and then tries to use it in a separate expression. This will cause a syntax error. Use a single expression like node -p \"require('./package.json').name + '-' + require('./package.json').version + '.vsix'\" or wrap it in an IIFE: node -p \"(p => p.name + '-' + p.version + '.vsix')(require('./package.json'))\".

Suggested change

	echo "vsix=$(node -p \"const p=require('./package.json'); p.name + '-' + p.version + '.vsix'\")" >> "$GITHUB_OUTPUT"
	echo "vsix=$(node -p \"(p => p.name + '-' + p.version + '.vsix')(require('./package.json'))\")" >> "$GITHUB_OUTPUT"