test: stabilize Node test timeouts

[ibgreen]

Summary

• Apply the configured Vitest testTimeout to the Node test project as well as the browser project.
• Preserve test coverage and assertions while allowing slower CI runners to use the repository-wide timeout setting.

Root cause

PR #3463 now passes its Parquet tests and the previously failing headless-browser checks, but Actions run 6494 failed because the LAS TypeScript-backend comparison exceeded Vitest's implicit 5-second Node-project timeout. The shared timeout was already calculated but was not forwarded to that project.

Validation

• This is the same one-line configuration change as commit b08e80e2e3, previously validated by the successful full Actions workflow on Add lightweight native decompression #3461.
• The draft changes only dev-modules/devtools-extensions/get-vitest-config.mjs.
• Actions run 6511 passed all jobs, including Node 22 and the full headless-browser suite.