dep-dev: Update dependency docker to v20.10.15

This MR contains the following updates:

Package	Type	Update	Change
docker	service-image	patch	20.10.14-dind -> 20.10.15-dind

---

Configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ 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, click this checkbox.

---

This MR has been generated by Renovate Bot.

---

Allure report

allure-report-publisher generated test report!

rspec: ✅ test report for 13078ce8

+------------------------------------------------------------------+
|                        behaviors summary                         |
+-------------+--------+--------+---------+-------+-------+--------+
|             | passed | failed | skipped | flaky | total | result |
+-------------+--------+--------+---------+-------+-------+--------+
| jobs        | 14     | 0      | 0       | 0     | 14    | ✅     |
| tasks       | 8      | 0      | 0       | 0     | 8     | ✅     |
| services    | 165    | 0      | 0       | 0     | 165   | ✅     |
| controllers | 24     | 0      | 0       | 0     | 24    | ✅     |
| system      | 9      | 0      | 0       | 0     | 9     | ✅     |
| models      | 3      | 0      | 0       | 0     | 3     | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+
| Total       | 223    | 0      | 0       | 0     | 223   | ✅     |
+-------------+--------+--------+---------+-------+-------+--------+