[renovate] Update mongo Docker tag to v8

This MR contains the following updates:

Package	Type	Update	Change
mongo	service-image	major	7 -> 8

---

Configuration

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

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

Rebasing: Whenever MR is behind base branch, 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.

.gitlab/ci/.test.yml

@@ -14,7 +14,7 @@ integration-test-gosdn:
         INTEGRATION_TEST_RABBITMQ_HOSTNAME: rabbitmq
         INTEGRATION_TEST_CONTROLLER_URL: gosdn:55055
     services:
-      - name: ${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/mongo:7
+      - name: ${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/mongo:8
         alias: mongo
       - name: ${CI_DEPENDENCY_PROXY_GROUP_IMAGE_PREFIX}/rabbitmq:4-management
         alias: rabbitmq