Fix REST API broken anchor and skip auto-generated page anchor checks (#60169)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: heiskr

content/rest/git/blobs.md

@@ -15,6 +15,6 @@ autogenerated: rest
 ## About Git blobs
 
 A Git blob (binary large object) is the object type used to store the contents of each file in a repository. The file's SHA-1 hash is computed and stored in the blob object. These endpoints allow you to read and write [blob objects](https://git-scm.com/book/en/v2/Git-Internals-Git-Objects)
-to your Git database on {% data variables.product.github %}. Blobs leverage [these custom media types](#custom-media-types-for-blobs). For more information about the use of media types in the API, see [AUTOTITLE](/rest/overview/media-types).
+to your Git database on {% data variables.product.github %}. Blobs leverage custom media types. For more information about the use of media types in the API, see [AUTOTITLE](/rest/overview/media-types).
 
 <!-- Content after this section is automatically generated -->

src/links/scripts/check-links-internal.ts

@@ -101,6 +101,14 @@ async function checkAnchorsOnPage(
 ): Promise<BrokenLink[]> {
   const brokenAnchors: BrokenLink[] = []
 
+  // Skip anchor checking on auto-generated pages (e.g., REST, GraphQL, webhooks).
+  // These pages have headings generated from OpenAPI/schema data at render time
+  // by transformers that aren't run during link checking, so same-page anchor
+  // links to those headings would always appear broken.
+  if (page.autogenerated) {
+    return brokenAnchors
+  }
+
   try {
     const html = await renderContent(page.markdown, context)
     const $ = load(html)