[8.1] [DOCS] Add Elastic Security breaking changes to Installation and Upgrade Guide for 8.1 (backport #2076) (#2081)

Co-authored-by: nastasha-solomon <79124755+nastasha-solomon@users.noreply.github.com>

Author: mergify[bot]

docs/en/install-upgrade/breaking.asciidoc

@@ -67,9 +67,9 @@ include::{es-repo-dir}/migration/migrate_8_1.asciidoc[tag=notable-breaking-chang
 ++++
 
 This list summarizes the most important breaking changes in {elastic-sec} {version}. For
-the complete list, go to {security-guide-all}/8.0/release-notes-header-8.0.0.html#breaking-changes-8.0.0[{elastic-sec} breaking changes].
+the complete list, go to {security-guide-all}/8.1/release-notes-header-8.1.0.html#breaking-changes-8.1.0[{elastic-sec} breaking changes].
 
-include::{security-repo-dir}/release-notes/8.0.asciidoc[tag=breaking-changes]
+include::{security-repo-dir}/release-notes/8.1.asciidoc[tag=breaking-changes]
 
 [[kibana-breaking-changes]]
 === {kib} breaking changes