ci: publish helm chart to ghcr

[davidspek]

What this PR does / why we need it:
This PR extends the CI to push the helm charts to GHCR so that users can easily install KServe using them.
Examples of the charts published from this PR can be seen here:
https://github.com/davidspek/kserve/pkgs/container/charts%2Fkserve
https://github.com/davidspek/kserve/pkgs/container/charts%2Fkserve-crd

Checklist:

• Have you added unit/e2e tests that prove your fix is effective or that this feature works?
• Has code been commented, particularly in hard-to-understand areas?
• Have you made corresponding changes to the documentation?

Release note:

ci: publish helm charts to GHCR

[yuzisun]

/lgtm
/approve

[oss-prow-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: davidspek, yuzisun

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• OWNERS [yuzisun]

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[gawsoftpl]

I have created new issue: #3331

@davidspek Hi I have trouble with install helm chart with oci registry

I received error 403

I have created token with public repo read only

echo $GHCR_PAT | helm registry login ghcr.io -u <username> --password-stdin

When execute helm install I received error 403. Charts for kserve required special privilege scope?

helm install --debug kserve-crd oci://ghcr.io/kserve/charts/kserve-crd --version 0.11.2
install.go:194: [debug] Original chart version: "0.11.2"
DEBU[0000] resolving                                     host=ghcr.io
DEBU[0000] do request                                    host=ghcr.io request.header.accept="application/vnd.docker.distribution.manifest.v2+json, application/vnd.docker.distribution.manifest.list.v2+json, application/vnd.oci.image.manifest.v1+json, application/vnd.oci.image.index.v1+json, */*" request.header.user-agent=Helm/3.11.1 request.method=HEAD url="https://ghcr.io/v2/kserve/charts/kserve-crd/manifests/0.11.2"
DEBU[0000] fetch response received                       host=ghcr.io response.header.content-length=73 response.header.content-type=application/json response.header.date="Sun, 24 Dec 2023 22:38:16 GMT" response.header.www-authenticate="Bearer realm=\"https://ghcr.io/token\",service=\"ghcr.io\",scope=\"repository:kserve/charts/kserve-crd:pull\"" response.header.x-github-request-id="AB80:3B3095:175D1DA:17FBFE1:6588B2D8" response.status="401 Unauthorized" url="https://ghcr.io/v2/kserve/charts/kserve-crd/manifests/0.11.2"
DEBU[0000] Unauthorized                                  header="Bearer realm=\"https://ghcr.io/token\",service=\"ghcr.io\",scope=\"repository:kserve/charts/kserve-crd:pull\"" host=ghcr.io
DEBU[0000] do request                                    host=ghcr.io request.header.accept="application/vnd.docker.distribution.manifest.v2+json, application/vnd.docker.distribution.manifest.list.v2+json, application/vnd.oci.image.manifest.v1+json, application/vnd.oci.image.index.v1+json, */*" request.header.user-agent=Helm/3.11.1 request.method=HEAD url="https://ghcr.io/v2/kserve/charts/kserve-crd/manifests/0.11.2"
DEBU[0001] fetch response received                       host=ghcr.io response.header.content-length=86 response.header.content-type=application/json response.header.date="Sun, 24 Dec 2023 22:38:17 GMT" response.header.docker-distribution-api-version=registry/2.0 response.header.x-github-request-id="AB80:3B3095:175D247:17FC052:6588B2D9" response.status="403 Forbidden" url="https://ghcr.io/v2/kserve/charts/kserve-crd/manifests/0.11.2"
Error: INSTALLATION FAILED: pulling from host ghcr.io failed with status code [manifests 0.11.2]: 403 Forbidden
helm.go:84: [debug] pulling from host ghcr.io failed with status code [manifests 0.11.2]: 403 Forbidden
INSTALLATION FAILED
main.newInstallCmd.func2
	helm.sh/helm/v3/cmd/helm/install.go:141
github.com/spf13/cobra.(*Command).execute
	github.com/spf13/cobra@v1.6.1/command.go:916
github.com/spf13/cobra.(*Command).ExecuteC
	github.com/spf13/cobra@v1.6.1/command.go:1044
github.com/spf13/cobra.(*Command).Execute
	github.com/spf13/cobra@v1.6.1/command.go:968
main.main
	helm.sh/helm/v3/cmd/helm/helm.go:83
runtime.main
	runtime/proc.go:250
runtime.goexit
	runtime/asm_amd64.s:1571