Update GitHub Actions workflow for VS Code extension publishing

[kasuken]

Revise the GitHub Actions workflow to trigger on merged pull requests, enhance package metadata handling, and update the extension version to 0.7.2.

[Copilot]

Pull Request Overview

Updates the GitHub Actions workflow for VS Code extension publishing by modifying the package metadata handling script to use string concatenation instead of template literals.

• Modified the package metadata reading script to use traditional string concatenation
• Enhanced the workflow's compatibility with different Node.js environments

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[Copilot]

[nitpick] The inline Node.js script is difficult to read and maintain. Consider extracting this logic to a separate script file or using a multi-line YAML block with proper formatting for better readability.

Suggested change

	node -e "const fs=require('fs'); const p=require('./package.json'); const out=process.env.GITHUB_OUTPUT; fs.appendFileSync(out, 'version=' + p.version + '\n'); fs.appendFileSync(out, 'name=' + p.name + '\n'); fs.appendFileSync(out, 'vsix=' + p.name + '-' + p.version + '.vsix\n');"
	node <<'EOF'
	const fs = require('fs');
	const p = require('./package.json');
	const out = process.env.GITHUB_OUTPUT;
	fs.appendFileSync(out, `version=${p.version}\n`);
	fs.appendFileSync(out, `name=${p.name}\n`);
	fs.appendFileSync(out, `vsix=${p.name}-${p.version}.vsix\n`);
	EOF