chore(deps): bump go from 1.20.7 to 1.21.1 (backport of #7799)

[kumahq]

Automatic cherry-pick of #7799 for branch release-2.1

Generated by action

cherry-picked commit 630cd8b
⚠️ ⚠️ ⚠️ Conflicts happened when cherry-picking! ⚠️ ⚠️ ⚠️

On branch release-2.1
Your branch is up to date with 'origin/release-2.1'.

You are currently cherry-picking commit 630cd8bee.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   .circleci/config.yml
	deleted by us:   .github/workflows/blackbox-tests.yaml
	deleted by us:   .github/workflows/golangci-lint.yml
	both modified:   .github/workflows/helm-release.yaml
	both modified:   .github/workflows/pr-comments.yaml
	deleted by us:   .github/workflows/release.yaml
	deleted by us:   .github/workflows/update-docs.yaml
	both modified:   .github/workflows/update-insecure-dependencies.yaml
	both modified:   go.mod
	both modified:   go.sum
	both modified:   mk/dependencies/deps.lock
	both modified:   mk/dev.mk

no changes added to commit (use "git add" and/or "git commit -a")