remove insecureSkipTLSVerify in helm chart

[chaosi-zju]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Backupground: insecureSkipTLSVerify=true means prohibit clientside from verifing the cert of serverside, this is an unsafe configuration, we can avoid unnecessary unsafe configurations.

This PR mainly aims to remove insecureSkipTLSVerify in helm chart.

Which issue(s) this PR fixes:

part of #4024

Special notes for your reviewer:

You can test helm install by following bash script:

#!/bin/bash

# clean old clusters and config
kind delete clusters --all; rm -r ~/.karmada/; rm ~/.kube/*.config; rm -r /etc/karmada
# please replace to your own local karmada repo path
cd /root/home/gopath/src/github.com/karmada
# create a Kind cluster
hack/create-cluster.sh karmada-host ~/.kube/karmada.config

export KUBECONFIG=~/.kube/karmada.config:~/.kube/karmada-apiserver.config

# pull images in advance and avoid duplicate downloads when each installation
for img in `cat charts/karmada/values.yaml | grep -C 1 'repository:' | sed 's/*karmadaImageVersion/latest/g' | awk -F ':' '{print $2}' | sed 's/\"//g' | xargs -n3 | awk '{print $1"/"$2":"$3}'`; do docker pull $img; kind load docker-image $img --name karmada-host; done

kubectl get pods -o wide -A

# helm install
helm install karmada -n karmada-system --create-namespace --dependency-update --set components={"descheduler"} ./charts/karmada --debug

# export karmada-apiserver kubeconfig
kubectl get secret -n karmada-system karmada-kubeconfig -o jsonpath={.data.kubeconfig} | base64 -d > ~/.kube/karmada-apiserver.config

Test result：

Does this PR introduce a user-facing change?:

none

[RainbowMango]

/lgtm
/approve

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RainbowMango

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• charts/OWNERS [RainbowMango]

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