Add Kerberos Migration Section

This links to the updated dependency coordinates

Issue gh-18773

Signed-off-by: Robert Winch <362503+rwinch@users.noreply.github.com>

docs/modules/ROOT/pages/migration/servlet/kerberos.adoc

@@ -0,0 +1,4 @@
+= Kerberos Migrations
+
+For users leveraging Spring Security's Kerberos support, the Maven  and Gradle Coordinates have been changed since the support was moved from an external module into Spring Security.
+See the xref:servlet/authentication/kerberos/introduction.adoc[Keberos documentation] for the new Maven and Gradle coordinates.