olm/operator: fix issue in wrapping error (#4309)

Randomly `run packagemanifests` fails with below error:
```
Failed to run packagemanifests: error approving install plan: Operation cannot be fulfilled on installplans.operators.coreos.com \"install-jp28s\": the object has been modified; please apply your changes to the latest version and try again
```

The reason is the way error wrapping while calling the
`retry.RetryOnConflict()`. Using '%w' for formatting the error keeps the
original error type unlike '%v'.

FIXES #4308

Author: avalluri

internal/olm/operator/registry/operator_installer.go

@@ -335,7 +335,7 @@ func (o OperatorInstaller) approveInstallPlan(ctx context.Context, sub *v1alpha1
 		// approve the install plan by setting Approved to true
 		ip.Spec.Approved = true
 		if err := o.cfg.Client.Update(ctx, &ip); err != nil {
-			return fmt.Errorf("error approving install plan: %v", err)
+			return fmt.Errorf("error approving install plan: %w", err)
 		}
 		return nil
 	}); err != nil {