@electron/packager's build process memory potentially leaked into final executable

Electron Packager bundles Electron-based application source code with a renamed Electron executable and supporting files into folders ready for distribution. A random segment of ~1-10kb of Node.js heap memory allocated either side of a known buffer will be leaked into the final executable. This memory _could_ contain sensitive information such as environment variables, secrets files, etc. This issue is patched in 18.3.1.