Update docker.elastic.co/elasticsearch/elasticsearch Docker tag to v8.15.3

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
docker.elastic.co/elasticsearch/elasticsearch (source)	docker	minor	8.14.3 -> 8.15.3

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Release Notes

elastic/elasticsearch (docker.elastic.co/elasticsearch/elasticsearch)

v8.15.3: Elasticsearch 8.15.3

Compare Source

Downloads: https://elastic.co/downloads/elasticsearch
Release notes: https://www.elastic.co/guide/en/elasticsearch/reference/8.15/release-notes-8.15.3.html

v8.15.2: Elasticsearch 8.15.2

Compare Source

Downloads: https://elastic.co/downloads/elasticsearch
Release notes: https://www.elastic.co/guide/en/elasticsearch/reference/8.15/release-notes-8.15.2.html

v8.15.1: Elasticsearch 8.15.1

Compare Source

Downloads: https://elastic.co/downloads/elasticsearch
Release notes: https://www.elastic.co/guide/en/elasticsearch/reference/8.15/release-notes-8.15.1.html

v8.15.0: Elasticsearch 8.15.0

Compare Source

Downloads: https://elastic.co/downloads/elasticsearch
Release notes: https://www.elastic.co/guide/en/elasticsearch/reference/8.15/release-notes-8.15.0.html

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