chore: add shell flag to prepare script

Author: nbbeeken

etc/prepare.js

@@ -3,7 +3,7 @@ var cp = require('child_process');
 var fs = require('fs');
 
 if (fs.existsSync('src')) {
-  cp.spawn('npm', ['run', 'build:dts'], { stdio: 'inherit' });
+  cp.spawn('npm', ['run', 'build:dts'], { stdio: 'inherit', shell: true });
 } else {
   if (!fs.existsSync('lib')) {
     console.warn('MongoDB: No compiled javascript present, the driver is not installed correctly.');