pnpm doesn't honor the npm setting script-shell while it should

[b4git]

pnpm version: 5.9.x

Code to reproduce the issue:

// just create a package.json in an empty directory with following content:
{
  "scripts": {
    "test": "echo $SHELL; shopt;"
  }
}

// Then, run the following commands: 
//  0. In Windows run command:  npm config set script-shell "C:\\Program Files\\Git\\bin\\bash.exe"
//   0. Or in Linux run:    npm config set script-shell "/usr/bin/bash"
//   1. npm test
//    2. pnpm test

Expected behavior: The results of npm test and pnpm test should be equivalent.

Actual behavior: Results are distinct

Additional information:

• node -v prints: v14.x
• Windows, OS X, or Linux?: All

[b4git]

Related Post: #2931