Nithtly Tekton tests fail with short-name resolution enforced but cannot prompt without a TTY

[mgencur]

Bug report

Buildah/Podman now enforce specifying the full image names unless disabled in a global Podman configuration file on the host. The error is as follows:

buildah --storage-driver=overlay bud --format=docker --tls-verify=true --no-cache -f ./test/test_images/helloworld/Dockerfile -t gcr.io/knative-boskos-90/kn-tekton-e2e-img/18859/helloworld:tkn .
        [pod/buildah-build-kn-create-2ghs7-buildah-build-tl6zk-pod-6zl4g/step-build] STEP 1: FROM golang:1.13 AS builder
        [pod/buildah-build-kn-create-2ghs7-buildah-build-tl6zk-pod-6zl4g/step-build] STEP 2: FROM alpine:3
        [pod/buildah-build-kn-create-2ghs7-buildah-build-tl6zk-pod-6zl4g/step-build] error creating build container: short-name resolution enforced but cannot prompt without a TTY
        [pod/buildah-build-kn-create-2ghs7-buildah-build-tl6zk-pod-6zl4g/step-build] Resolved "alpine" as an alias (/etc/containers/registries.conf.d/000-shortnames.conf)
        [pod/buildah-build-kn-create-2ghs7-buildah-build-tl6zk-pod-6zl4g/step-digest-to-results] 2021/05/09 13:11:23 Skipping step because a previous step failed

The error can be seen here: https://prow.knative.dev/view/gs/knative-prow/logs/ci-knative-client-tekton/1391377492714983424

Expected behavior

The Tekton tests run successfully.

Steps to reproduce the problem

See the nightly job at https://testgrid.k8s.io/r/knative-own-testgrid/client#tekton