fix: load MathJax components via file:// URLs in the Node oracle

The tests workflow fails on windows-latest: MathJax's node entry
resolves components to plain absolute paths
(D:/.../node_modules/mathjax/input/tex.js) and loads them with
import(), but Node's ESM loader rejects absolute paths without a URL
scheme on Windows ("Only URLs with a scheme in: file, data, and node
are supported ... Received protocol 'd:'"). MathJax's own context.path
converter deliberately skips the file:// prefix in CJS contexts, so
the CJS entry (require('mathjax')) cannot produce import()-compatible
paths on Windows.

Override the loader's require function to convert absolute paths to
file:// URLs (pathToFileURL) before importing; relative paths and
node: specifiers pass through unchanged. Behavior on POSIX is
unchanged (file:// URLs are equally valid there).

Author: gsvgit

utils/check_math_snippets_node.cjs

@@ -14,6 +14,9 @@
  */
 'use strict';
 
+const path = require('node:path');
+const { pathToFileURL } = require('node:url');
+
 const MERROR_RE = /<merror[^>]*>([\s\S]*?)<\/merror>/g;
 
 function collapse(s) {
@@ -38,7 +41,15 @@ function main() {
     }
     require('mathjax')
       .init({
-        loader: { load: ['input/tex'] },
+        loader: {
+          load: ['input/tex'],
+          // MathJax's node entry resolves components to plain absolute
+          // paths and loads them with import(); Node's ESM loader rejects
+          // absolute paths without a URL scheme on Windows ("Received
+          // protocol 'd:'"), so convert them to file:// URLs.
+          require: (file) =>
+            import(path.isAbsolute(file) ? pathToFileURL(file).href : file),
+        },
         startup: { typeset: false },
       })
       .then((MathJax) => {