fix(node): duplicate node_module suffixes (#19222)

Noticed that we're checking more module paths than necessary. In
particular the module path array contains a couple of entries with a
duplicated `node_modules/node_modules` suffix.

```js
[
    // ... more entries before here, where some also contain duplicate suffixes
    "/Users/marvinhagemeister/dev/preact-render-to-string/node_modules/.deno/node_modules",
    "/Users/marvinhagemeister/dev/preact-render-to-string/node_modules/node_modules", // <-- duplicate suffix
    "/Users/marvinhagemeister/dev/preact-render-to-string/node_modules",
    "/Users/marvinhagemeister/dev/node_modules",
    "/Users/marvinhagemeister/node_modules",
    "/Users/node_modules",
    "/node_modules",
    "/node_modules"  // <-- duplicate entry
]
```

This was caused by a misunderstanding in how Rust's
[`Path::ends_with()`](https://doc.rust-lang.org/std/path/struct.Path.html#method.ends_with)
works. It's designed to match on whole path segments and the suffix
`/node_modules` is not that, except for the root entry. This meant that
our check for if the path already ended with `node_module` always
returned `false`. Removing the leading slash fixes that.

While we're at it, we can remove the last condition where we explicitly
added the root `/node_modules` entry since the while loop prior to that
takes care of it already.

1 files changed, 5 insertions, 0 deletions

diff --git a/ext/node/polyfills/01_require.js b/ext/node/polyfills/01_require.js
index 394015e31..508a32e12 100644
--- a/ext/node/polyfills/01_require.js
+++ b/ext/node/polyfills/01_require.js
@@ -607,6 +607,11 @@ Module._findPath = function (request, paths, isMain, parentPath) {
   return false;
 };
 
+/**
+ * Get a list of potential module directories
+ * @param {string} fromPath The directory name of the module
+ * @returns {string[]} List of module directories
+ */
 Module._nodeModulePaths = function (fromPath) {
   return ops.op_require_node_module_paths(fromPath);
 };