Bump elasticsearch-dsl from 8.15.0 to 8.16.0 in /requirements (#388)

Bumps [elasticsearch-dsl](https://github.com/elasticsearch/elasticsearch-dsl-py) from 8.15.0 to 8.16.0.
- [Release notes](https://github.com/elasticsearch/elasticsearch-dsl-py/releases)
- [Changelog](https://github.com/elastic/elasticsearch-dsl-py/blob/main/Changelog.rst)
- [Commits](elastic/elasticsearch-dsl-py@v8.15.0...v8.16.0)

---
updated-dependencies:
- dependency-name: elasticsearch-dsl
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/project-requirements.txt

@@ -1,7 +1,7 @@
 celery==5.4.0
 
 # if you change this, update the documentation
-elasticsearch-dsl==8.15.0
+elasticsearch-dsl==8.16.0
 
 Django==4.2.15
 djangorestframework==3.15.2