🌱 lint: enable revive if-return check and fix findings

[oscr]

What this PR does / why we need it:

Enables the revive if-return check and fixes the findings.

internal/controllers/clusterclass/clusterclass_controller_test.go:128:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := referenceExistsWithCorrectKindAndAPIVersion(actualClusterClass.Spec.Infrastructure.Ref,
		builder.GenericInfrastructureClusterTemplateKind,
		builder.InfrastructureGroupVersion); err != nil {
		return err
	}
internal/controllers/clusterclass/clusterclass_controller_test.go:227:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := referenceExistsWithCorrectKindAndAPIVersion(mdClass.Template.Bootstrap.Ref,
		builder.GenericBootstrapConfigTemplateKind,
		builder.BootstrapGroupVersion); err != nil {
		return err
	}
internal/runtime/client/client.go:111:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := c.registry.WarmUp(extensionConfigList); err != nil {
		return err
	}
internal/controllers/topology/cluster/reconcile_state.go:193:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := r.callAfterClusterUpgrade(ctx, s); err != nil {
		return err
	}
internal/controllers/topology/cluster/cluster_controller_test.go:840:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := referenceExistsWithCorrectKindAndAPIVersion(cluster.Spec.ControlPlaneRef,
		builder.TestControlPlaneKind,
		builder.ControlPlaneGroupVersion); err != nil {
		return err
	}
internal/controllers/topology/cluster/cluster_controller_test.go:1026:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := assertTemplateClonedFromNameAnnotation(got); err != nil {
		return err
	}
cmd/clusterctl/client/cluster/cert_manager.go:292:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := newCRDMigrator(c).Run(ctx, objs); err != nil {
		return err
	}
cmd/clusterctl/client/cluster/proxy.go:193:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
	if err := retryWithExponentialBackoff(connectBackoff, func() error {
		_, err := client.New(config, client.Options{Scheme: localScheme})
		return err
	}); err != nil {
		return err
	}


hack/tools/mdbook/tabulate/tabulate.go:78:2: if-return: redundant if ...; err != nil check, just return error instead. (revive)
        if err := plugin.EachCommand(&input.Book, "/tabs", func(chapter *plugin.BookChapter, args string) (string, error) {
                return "</div></div>", nil
        }); err != nil {
                return err
        }

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #7449

[oscr]

/test pull-cluster-api-test-main

[fabriziopandini]

nit: can we add a comment explaining why we need these lines?

[oscr]

Do you mean for each specific case? It's in the "Disable linters for conversion" section starting on L266

[fabriziopandini]

just a comment for L273 (text) and one for L274 (path) should be enough
the first one is a little bit opaque, why is this necessary?
the second instead seems kind of intuitive (skip the check for ... even if I'm not sure why are we ignoring api|types|test

[alexander-demicev]

if someone wanted to wrap the error and add more context to it, will the linter complain?

[oscr]

I think that would be fine. I just removed the err assignment since it wasn't needed as the implementation is right now.

[oscr]

/test pull-cluster-api-test-mink8s-main

[vincepri]

/approve
/lgtm

Good job on also adding comments in golanci-lint!

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: vincepri

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