security/vuxml: Document remaining Erlang/OTP vulnerabilities

Upstream published 16 advisories alongside OTP 29.0.6, 28.5.0.6 and
27.3.4.17. CVE-2026-75538 already had an entry; add a combined one for
the other 15, which share the same affected packages and fixed versions.
Most are in the inets httpd and httpc implementations: HTTP request
smuggling, two mod_auth authentication bypasses and several denial of
service issues, plus unbounded integer conversion in stdlib, snmp and
eldap.

Also add the now-published GHSA reference to the CVE-2026-75538 entry.