Turbopack: don't match dynamic pattern for node_modules packages (#83176)
This code would previously pull in every single package in node_modules
```
var path = require("path");
var dir = foo;
if (bar) {
dir = process.cwd();
}
path.join(dir, "node_modules");
```
Now, `node_modules/<dynamic>` doesn't match every single package anymore. It effectively thinks that `node_modules` is an empty folder when enumerating it.