CI: avoid Playwright Ubuntu install hang

[forhappy]

Summary

• Pin Node.js 24.15.0 for the Ubuntu CI jobs that run Playwright browser installation.
• Apply the same pin to the manual VS Code release workflow.

The previous 0.3.17 release PR merged before this follow-up fix was pushed, so this PR intentionally contains only the CI workaround.

Motivation

The Ubuntu 24.04 npx playwright install --with-deps chromium step stalled indefinitely in both javascript-and-vscode and code-graph-v1-fixtures. Playwright's documented issue reports Node 24.15 as the workaround for this browser-extraction hang.

Validation

• Workflow YAML parsed successfully with Ruby's YAML parser.
• The release branch remains based on the merged 0.3.17 tree.
• Local JavaScript, Playwright, Rust, and code-graph gates passed before the CI stall.