ci: use relative links in security-model.adoc (#2838)

Follow-up to #2836. That PR was squash-merged with only its first commit
(placeholder escaping); the relative-link commit was pushed afterwards and
never merged, so camel-kamelets main still carries 4 absolute
https://camel.apache.org/... links. They are now the sole remaining
camel/relative-links failure in the camel-website check:html step (4 errors
in camel-kamelets/next/security-model.html), keeping every camel-website PR
red.

Convert the 4 in-site links to root-relative link: macros (link:/security/,
link:/manual/security-model.html), matching apache/camel core
security-model.adoc (apache/camel#23224) and the sibling subproject fixes
(apache/camel-kafka-connector#1774, apache/camel-quarkus#8661). The merged
placeholder escaping is left intact; private-security@camel.apache.org email
references are unchanged. Documentation-only; same link targets, rendered
relative.

Signed-off-by: Andrea Cosentino <ancosen@gmail.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: oscerd

docs/modules/ROOT/pages/security-model.adoc

@@ -9,7 +9,7 @@ hardened in a Kamelet template or addressed by the deployment.
 
 The Kamelet Catalog is an *Apache Camel sub-project*. It does not define its own
 trust model from scratch: it *specialises* the
-https://camel.apache.org/manual/security-model.html[Apache Camel Security Model]
+link:/manual/security-model.html[Apache Camel Security Model]
 for the specific shape of a Kamelet (a pre-written, PMC-reviewed Camel route
 template distributed as YAML). Where this document is silent, the Camel Security
 Model governs. Where they overlap, this document is the more specific authority
@@ -441,7 +441,7 @@ change matches this model:
 
 The Kamelet Catalog uses the standard Apache Camel / ASF vulnerability process:
 
-* Read https://camel.apache.org/security/[Apache Camel Security].
+* Read link:/security/[Apache Camel Security].
 * Email `private-security@camel.apache.org` with the affected catalog
   version(s), the specific Kamelet, and a proof of concept that demonstrates the
   trust-boundary breach *through a shipped template in its default
@@ -577,10 +577,10 @@ revise this page rather than make an ad-hoc call.
 
 == Related documents
 
-* https://camel.apache.org/manual/security-model.html[Apache Camel Security
+* link:/manual/security-model.html[Apache Camel Security
   Model] - the parent model this page specialises.
 * xref:development.adoc[Kamelets Developer Guide] - how Kamelets are authored.
 * xref:apis/spec.adoc[Kamelet CRD specification] - the YAML contract.
-* https://camel.apache.org/security/[Apache Camel Security] - the public
+* link:/security/[Apache Camel Security] - the public
   advisory index and reporting process.
 * `SECURITY.md` (repository root) - the GitHub-rendered security pointer.