[Chore] Remove unused module (#214018)

## Summary

Remove unused module.

I noticed this doing some investigations, and thought to tidy this up.

### Checklist

Check the PR satisfies following conditions. 

Reviewers should verify this PR satisfies this list as well.

- [x] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)
- [x]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [x] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [x] This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [x] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

src/platform/plugins/shared/kibana_utils/public/index.ts

@@ -35,7 +35,6 @@ export {
   DuplicateField,
 } from '../common/errors';
 export {
-  RenderCompleteListener,
   RenderCompleteDispatcher,
   dispatchRenderComplete,
   dispatchRenderStart,

src/platform/plugins/shared/kibana_utils/public/render_complete/index.ts

@@ -7,7 +7,6 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-export { RenderCompleteListener } from './render_complete_listener';
 export {
   dispatchRenderStart,
   dispatchRenderComplete,

src/platform/plugins/shared/kibana_utils/public/render_complete/render_complete_listener.ts

@@ -1,42 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the "Elastic License
- * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
- * Public License v 1"; you may not use this file except in compliance with, at
- * your election, the "Elastic License 2.0", the "GNU Affero General Public
- * License v3.0 only", or the "Server Side Public License, v 1".
- */
-
-export class RenderCompleteListener {
-  private readonly attributeName = 'data-render-complete';
-
-  constructor(private readonly element: HTMLElement) {
-    this.setup();
-  }
-
-  public destroy = () => {
-    this.element.removeEventListener('renderStart', this.start);
-    this.element.removeEventListener('renderComplete', this.complete);
-  };
-
-  public setup = () => {
-    this.element.setAttribute(this.attributeName, 'false');
-    this.element.addEventListener('renderStart', this.start);
-    this.element.addEventListener('renderComplete', this.complete);
-  };
-
-  public disable = () => {
-    this.element.setAttribute(this.attributeName, 'disabled');
-    this.destroy();
-  };
-
-  private start = () => {
-    this.element.setAttribute(this.attributeName, 'false');
-    return true;
-  };
-
-  private complete = () => {
-    this.element.setAttribute(this.attributeName, 'true');
-    return true;
-  };
-}