[ML] Transform test fix for testCreateLatestFunction (#66293)

closes https://github.com/elastic/elasticsearch/issues/66292

client/rest-high-level/src/test/java/org/elasticsearch/client/transform/transforms/latest/LatestConfigTests.java

@@ -23,12 +23,16 @@ import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.test.AbstractXContentTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.function.Predicate;
 
 public class LatestConfigTests extends AbstractXContentTestCase<LatestConfig> {
 
     public static LatestConfig randomLatestConfig() {
-        return new LatestConfig(randomList(5, () -> randomAlphaOfLengthBetween(1, 10)), randomAlphaOfLengthBetween(1, 10));
+        return new LatestConfig(
+            new ArrayList<>(randomUnique(() -> randomAlphaOfLengthBetween(1, 10), randomIntBetween(1, 10))),
+            randomAlphaOfLengthBetween(1, 10)
+        );
     }
 
     @Override

client/rest-high-level/src/test/java/org/elasticsearch/client/transform/transforms/latest/hlrc/LatestConfigTests.java

@@ -25,6 +25,7 @@ import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.xpack.core.transform.transforms.latest.LatestConfig;
 
 import java.io.IOException;
+import java.util.ArrayList;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
@@ -33,7 +34,10 @@ public class LatestConfigTests
         extends AbstractResponseTestCase<LatestConfig, org.elasticsearch.client.transform.transforms.latest.LatestConfig> {
 
     public static LatestConfig randomLatestConfig() {
-        return new LatestConfig(randomList(1, 10, () -> randomAlphaOfLengthBetween(1, 10)), randomAlphaOfLengthBetween(1, 10));
+        return new LatestConfig(
+            new ArrayList<>(randomUnique(() -> randomAlphaOfLengthBetween(1, 10), randomIntBetween(1, 10))),
+            randomAlphaOfLengthBetween(1, 10)
+        );
     }
 
     @Override

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/transform/transforms/latest/LatestConfigTests.java

@@ -15,6 +15,7 @@ import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.xpack.core.transform.transforms.AbstractSerializingTransformTestCase;
 
 import java.io.IOException;
+import java.util.ArrayList;
 
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
@@ -25,7 +26,10 @@ import static org.hamcrest.Matchers.nullValue;
 public class LatestConfigTests extends AbstractSerializingTransformTestCase<LatestConfig> {
 
     public static LatestConfig randomLatestConfig() {
-        return new LatestConfig(randomList(1, 10, () -> randomAlphaOfLengthBetween(1, 10)), randomAlphaOfLengthBetween(1, 10));
+        return new LatestConfig(
+            new ArrayList<>(randomUnique(() -> randomAlphaOfLengthBetween(1, 10), randomIntBetween(1, 10))),
+            randomAlphaOfLengthBetween(1, 10)
+        );
     }
 
     @Override