Decouple the esql plugin from the ML plugin by removing explicit dependency.

Author: afoucret

x-pack/plugin/esql/build.gradle

@@ -23,7 +23,7 @@ esplugin {
   name = 'x-pack-esql'
   description = 'The plugin that powers ESQL for Elasticsearch'
   classname = 'org.elasticsearch.xpack.esql.plugin.EsqlPlugin'
-  extendedPlugins = ['x-pack-esql-core', 'lang-painless', 'x-pack-ml']
+  extendedPlugins = ['x-pack-esql-core', 'lang-painless']
 }
 
 base {
@@ -34,7 +34,6 @@ dependencies {
   compileOnly project(path: xpackModule('core'))
   compileOnly project(':modules:lang-painless:spi')
   compileOnly project(xpackModule('esql-core'))
-  compileOnly project(xpackModule('ml'))
   implementation project(xpackModule('kql'))
   implementation project('compute')
   implementation project('compute:ann')
@@ -53,6 +52,7 @@ dependencies {
   testImplementation project(path: xpackModule('enrich'))
   testImplementation project(path: xpackModule('spatial'))
   testImplementation project(path: xpackModule('kql'))
+  testImplementation project(path: xpackModule('ml'))
 
   testImplementation project(path: ':modules:reindex')
   testImplementation project(path: ':modules:parent-join')

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/logical/ChangePoint.java

@@ -30,7 +30,6 @@
  * Plan that detects change points in a list of values. See also:
  * <ul>
  * <li> {@link org.elasticsearch.compute.operator.ChangePointOperator}
- * <li> {@link org.elasticsearch.xpack.ml.aggs.changepoint.ChangePointDetector}
  * </ul>
  *
  * ChangePoint should always run on the coordinating node after the data is collected