Lint issues

[mattfarina]

Running golangci-lint on master is generating the following issues:

pkg/objectset/objectset.go:116:8: Error return value of `o.err` is not checked (errcheck)
		o.err(errors.Wrapf(err, "failed to add %T", obj))
		     ^
pkg/objectset/objectset.go:122:8: Error return value of `o.err` is not checked (errcheck)
		o.err(errors.Wrapf(err, "failed to add %T", obj))
		     ^
pkg/apply/desiredset_process.go:213:8: Error return value of `o.err` is not checked (errcheck)
		o.err(err)
		     ^
pkg/relatedresource/changeset.go:86:15: Error return value is not checked (errcheck)
				runResolve(meta.GetNamespace(), meta.GetName(), ro)
				          ^
pkg/needacert/needacert.go:260:23: Error return value of `h.locker.Unlock` is not checked (errcheck)
	defer h.locker.Unlock(lockKey)
	                     ^
pkg/controller-gen/main.go:32:2: var `t` is unused (unused)
	t = true
	^
pkg/schemas/mappers/enum.go:15:2: field `field` is unused (unused)
	field string
	^
pkg/apply/desiredset_apply.go:92:11: S1012: should use `time.Since` instead of `time.Now().Sub` (gosimple)
		if d := time.Now().Sub(t); d.Seconds() > 1 {
		        ^
pkg/git/git.go:10:2: SA1019: "io/ioutil" has been deprecated since Go 1.19: As of Go 1.16, the same functionality is now provided by package io or package os, and those implementations should be preferred in new code. See the specific function documentation for details. (staticcheck)
	"io/ioutil"
	^
pkg/apply/desiredset_compare.go:7:2: SA1019: "io/ioutil" has been deprecated since Go 1.19: As of Go 1.16, the same functionality is now provided by package io or package os, and those implementations should be preferred in new code. See the specific function documentation for details. (staticcheck)
	"io/ioutil"

[KevinJoiner]

Do we know how this is getting passed CI?