ci: update automatic linting and fix issues

Context

The static-analysis job runs the golangci-lint linter. The job uses the old image registry.gitlab.com/gitlab-org/gitlab-build-images:golangci-lint-alpine which was deprecated in %16.10.

Problem

The linter job has been silently failing because we have a condition set as -issues-exit-code 0, for example https://gitlab.com/gitlab-org/container-registry/-/jobs/7380948519

Solution

1. Update the linter image to use the upstream version of golangci-lint
2. Make the static-analysis pass on failure temporarily allow_failure: true
3. Fix linting issues in small MRs to make reviews smaller and easy to follow
4. Once all issues have been fixed, remove the allow_failure flag from the job

Linters

Linter	MR	Who
unused	!1879 (merged)	@jaime
gosimple	!1864 (merged)	@jaime
staticcheck	!1757 (merged)	@jaime
gofumpt	!1710 (merged)	@jaime
depguard	!1695 (merged)	@jaime
govet	!1902 (merged)	@jaime
stylecheck	!1913 (merged)	@vespian_gl
nakedret	!1909 (merged)	@vespian_gl
whitespace	!1910 (merged)	@vespian_gl
ineffassign	!1907 (merged)	@vespian_gl
unparam	!1903 (merged)	@jaime
revive	!1927 (merged) ....	@vespian_gl
gosec	!1923 (merged) !1922 (merged)	@vespian_gl