pnpm: Add pnpmfile hack for outdated estimo deps (#40549)

Estimo doesn't seem to be actively maintained despite having strictly
versioned deps. Add a pnpmfile hack to change these to caret deps, so we
can update `ws` and `nanoid` to versions that don't have dependabot
complaining.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/12265456218

Upstream-Ref: Automattic/jetpack@3c012a8

Author: tbradsha