Move diagnostics to `diagnostics` domain (#24931).

pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java

Index: pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
diff --git a/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java b/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
index a83490fcd69382786ba3f54a48b179fa4029304c..43a520fbc00a19cd6e4cf59d1cc6a057fa28b75f 100644
--- a/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
+++ b/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
@@ -273,6 +273,13 @@ public interface AnalysisServer {
   public void completion_getSuggestions(String file, int offset, GetSuggestionsConsumer consumer);
 
   /**
+   * {@code diagnostic.getDiagnostics}
+   *
+   * Return server diagnostics.
+   */
+  public void diagnostic_getDiagnostics(GetDiagnosticsConsumer consumer);
+
+  /**
    * {@code edit.format}
    *
    * Format the contents of a single file. The currently selected region of text is passed in so that
@@ -443,13 +450,6 @@ public interface AnalysisServer {
   public void execution_setSubscriptions(List<String> subscriptions);
 
   /**
-   * {@code experimental.getDiagnostics}
-   *
-   * Return server diagnostics.
-   */
-  public void experimental_getDiagnostics(GetDiagnosticsConsumer consumer);
-
-  /**
    * Return {@code true} if the socket is open.
    */
   public boolean isSocketOpen();