Update golang Docker tag to v1.21.6

This MR contains the following updates:

Package	Type	Update	Change
golang	final	minor	1.13.5 -> 1.21.6

---

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 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.

mentioned in issue #40

changed title from Update golang Docker tag to v1.21.5 to Update golang Docker tag to v1.21.6

changed the description

added 25 commits

• 61fbde98...5bc7a162 - 24 commits from branch master
• 326aacda - Update golang Docker tag to v1.21.6

Compare with previous version

mentioned in commit 14e02171

merged