Update tomcat Docker tag to v9.0.56

This MR contains the following updates:

Package	Type	Update	Change
tomcat	ironbank-docker	patch	9.0.55-jdk11-openjdk -> 9.0.56-jdk11-openjdk
tomcat		patch	9.0.55 -> 9.0.56
tomcat	stage	patch	9.0.55-jdk11-openjdk -> 9.0.56-jdk11-openjdk

---

Configuration

📅 Schedule: 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 these updates again.

---

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

---

This MR has been generated by Renovate Bot.