tools: apply more stringent blank-line linting for markdown files

Update remark-preset-lint-node to 1.9.0, which adds linting for
multiple consecutive blank lines.

PR-URL: https://github.com/nodejs/node/pull/29447


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>