CI build tests should use combined build image and build Windows images

[abayer]

As revealed by #5174, we're not actually build Windows images in pull-tekton-pipeline-build-tests, which resulted in code that can't compile on Windows slipping through in a PR. We should be setting Windows-supporting combined build images in ko_resolve in test/presubmit-tests.sh in the same sort of way we are in

pipeline/tekton/publish.yaml

Lines 96 to 113 in 94055d9

	# Combine Distroless with a Windows base image, used for the entrypoint image.
	COMBINED_BASE_IMAGE=$(go run ./vendor/github.com/tektoncd/plumbing/cmd/combine/main.go \
	ghcr.io/distroless/static \
	mcr.microsoft.com/windows/nanoserver:ltsc2022 \
	${CONTAINER_REGISTRY}/$(params.package)/combined-base-image:latest)
	cat <<EOF > ${PROJECT_ROOT}/.ko.yaml
	# This matches the value configured in .ko.yaml
	defaultBaseImage: ghcr.io/distroless/static
	baseImageOverrides:
	# Use the combined base image for images that should include Windows support.
	$(params.package)/cmd/entrypoint: ${COMBINED_BASE_IMAGE}
	$(params.package)/cmd/nop: ${COMBINED_BASE_IMAGE}
	$(params.package)/cmd/workingdirinit: ${COMBINED_BASE_IMAGE}
	# This matches values configured in .ko.yaml
	$(params.package)/cmd/git-init: ghcr.io/distroless/git
	EOF

We can probably just use gcr.io/tekton-releases/github.com/tektoncd/pipeline/combined-base-image:latest for that combined base image, rather than generating a new one each time.

/kind bug

[abayer]

I'm going to wait to open a PR until #5174 is dealt with, since the build would fail anyway.

[abayer]

...ok, yeah, I didn't wait to open a PR. 🤷

[vdemeester]

cc @imjasonh