Multiple pullSecrets for same registry does not work

When having multiple pullSecrets for the same registry in the same Service Account, Knative fails to detect the correct set of credentials and fails at the first. The [kubelet has a loop build in that allows this setup](https://github.com/kubernetes/kubernetes/blob/a55bd631728590045b51a4f65bba31aed1415571/pkg/kubelet/kuberuntime/kuberuntime_image.go#L59-L76).

## What version of Knative?

1.1.0

## Expected Behavior

To attempt each imagePullSecret in the associated Service Account when resolving the tag of an image and continue deploying the revision.

## Actual Behavior

It fails at the first pull secret, from which the credentials do not match and does not attempt the next pull secret.

## Steps to Reproduce the Problem

1. Create 2 `kubernetes.io/dockerconfigjson`-secrets for the same registry with different username/password.
2. Create a Service Account with both secrets.
3. Create a kservice with the above created Service Account, and include 2 containers in the pod whereby:
- The first container should only be allowed to be pulled from the first set of credentials (used in the first secret).
- The second container should only be allowed to be pulled from the registry using the second set of credentials (used in the second secret).

## Workaround
We disabled tag resolving by setting `registries-skipping-tag-resolving` in `config-deployment` to our registry.