Sweep every reference link for rot

The first full pass over all 60,039 reference URLs: 1,566 answer 404 or
410, which removes 2,663 links from 2,419 entries and 2,445 lines from
references.txt. Anything that timed out, refused a HEAD or answered 403
kept its link.

The weekly job takes it from here on a five-week cycle, so this only had to
be paid once.

.github/link_audit_state.json

@@ -1,4 +1,4 @@
 {
-  "cursor": "0-9194/node-poc-http-smuggling",
+  "cursor": "0-d3y/CVE-2023-29489",
   "reference_cursor": "http://lorexxar.cn/2017/07/11/Some%20Vulnerability%20for%20FineCMS%20through%202017.7.11/#Reflected-XSS-in-get-image-php"
 }