Remove xref <<migration-api-deprecation

docs/reference/migration/index.asciidoc

@@ -3,28 +3,26 @@
 
 [partintro]
 --
-This section describes the breaking changes and deprecations introduced in this release 
-and previous minor versions. 
+This section describes the breaking changes and deprecations introduced in this release
+and previous minor versions.
 
-As {es} introduces new features and improves existing ones, 
+As {es} introduces new features and improves existing ones,
 the changes sometimes make older settings, APIs, and parameters obsolete.
-The obsolete functionality is typically deprecated in a minor release and 
+The obsolete functionality is typically deprecated in a minor release and
 removed in the subsequent major release.
 This enables applications to continue working unchanged across most minor version upgrades.
-Breaking changes introduced in minor releases are generally limited to critical security fixes 
+Breaking changes introduced in minor releases are generally limited to critical security fixes
 and bug fixes that correct unintended behavior.
 
 To get the most out of {es} and facilitate future upgrades, we strongly encourage migrating
-away from using deprecated functionality as soon as possible. 
+away from using deprecated functionality as soon as possible.
 
 To give you insight into what deprecated features you're using, {es}:
 
 - Returns a `Warn` HTTP header whenever you submit a request that uses deprecated functionality.
-- <<deprecation-logging, Logs deprecation warnings>> when deprecated functionality is used. 
-- <<migration-api-deprecation, Provides a deprecation info API>> that scans a cluster's configuration 
-and mappings for deprecated functionality.
+- <<deprecation-logging, Logs deprecation warnings>> when deprecated functionality is used.
 
-For more information about {minor-version}, 
+For more information about {minor-version},
 see the <<release-highlights>> and <<es-release-notes>>.
 For information about how to upgrade your cluster, see <<setup-upgrade>>.
 

docs/reference/migration/migrate_7_0/migrate_to_java_time.asciidoc

@@ -52,9 +52,6 @@ If you don't use custom date formats, you can skip the rest of this guide.
 Most custom date formats are compatible. However, several require
 an update.
 
-To see if your date format is impacted, use the <<migration-api-deprecation,deprecation info API>>
-or the {kibana-ref}/upgrade-assistant.html[Kibana upgrade assistant].
-
 [[java-time-migration-incompatible-date-formats]]
 ==== Incompatible date formats
 Custom date formats containing the following joda-time literals should be