automation: Update docker-mastodon_elasticsearch Docker tag to v8.15.5

This MR contains the following updates:

Package	Update	Change
docker-mastodon_elasticsearch (source)	patch	8.15.4 -> 8.15.5

---

Release Notes

elastic/elasticsearch (docker-mastodon_elasticsearch)

v8.15.5: Elasticsearch 8.15.5

Compare Source

Downloads: https://elastic.co/downloads/elasticsearch Release notes: https://www.elastic.co/guide/en/elasticsearch/reference/8.15/release-notes-8.15.5.html

---

Configuration

Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

Automerge: Enabled.

Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

Ignore: Close this MR and you won't be reminded about this update again.

---

• If you want to rebase/retry this MR, check this box

---

This MR has been generated by Renovate Bot.