Fixup call execvpe wrapper instead of LibC.execvpe (#16321)

Fixup for unintended change in #16286. It should've stayed using the `execvpe` wrapper from #16294

Fixes #16286 (comment)

Author: straight-shoota

src/crystal/system/unix/process.cr

@@ -354,7 +354,7 @@ struct Crystal::System::Process
 
     ::Dir.cd(chdir) if chdir
 
-    lock_write { LibC.execvp(*prepared_args) }
+    lock_write { execvpe(*prepared_args, LibC.environ) }
   end
 
   private def self.execvpe(command, argv, envp)