Output a meaningful message if git is not available

Related to nodejs/node#33458

Author: 0x2b3bfa0

src/cml.js

@@ -103,6 +103,10 @@ const fixGitSafeDirectory = () => {
       .split(/[\r\n]+/)
       .includes(directory) || gitConfigSafeDirectory(directory);
 
+  // Fail meaningfully if git is not available,
+  // see https://github.com/nodejs/node/issues/33458
+  spawnSync('git');
+  
   // Fix for git>=2.36.0
   addSafeDirectory('*');