test: run CI on Windows and macOS

[kilisamemarisaaa]

What

Exercise compression's test suite on Windows and macOS in CI, while preserving the existing Ubuntu/nvm matrix for historical Node.js versions.

Why

The current workflow only runs its tests on ubuntu-latest. Adding native Windows and macOS coverage follows the cross-platform CI pattern already merged in expressjs/multer#1464 and proposed in expressjs/body-parser#759 and expressjs/morgan#379.

Changes

• Add a test-cross-platform job using actions/setup-node.
• Run Node.js 10.x–25.x on windows-latest; Node.js 10.x–21.x remain informational until measured.
• Run Node.js 16.x–25.x on macos-latest; 16.x–21.x are informational and 22.x+ are required checks.
• Keep the existing test job unchanged so the historical Node.js 0.8–25.x Ubuntu/nvm coverage and existing check names remain intact.
• Do not upload coverage artifacts from the cross-platform job, so the coverage-node-* artifact names consumed by the coverage job stay unambiguous.
• Reuse the repository's pinned actions/checkout and actions/setup-node SHAs.

Verification

• Windows local baseline on Node.js v24.12.0: 56 passing.
• npm run lint passes locally.
• Workflow YAML parses successfully and git diff --check is clean.

As this is the first contribution from this fork to compression, the workflow may require maintainer approval before GitHub Actions runs it.