Mk/Uses/electron.mk: Ensure reproducibility of node modules tarball for pnpm>=11

When pnpm is used as the node package manager, the package index has
been stored as JSON files under pnpm store's index directory prior to
pnpm version 11. Starting from pnpm 11, the package index has become a
single SQLite database stored as index.db.

To ensure reproducibility of the package index, we now have to unpack
the database, normalize the timestamps and the permissions of
files/directories stored in the index, and pack it again into an
SQLite database.

For more details on pnpm store v11, visit the URL:
https://pnpm.io/blog/releases/11.0#store-v11