provider: check cert expiration locally

[arno01]

We are currently verifying if the certificate expires within the chain, as indicated in this section of the code - https://github.com/akash-network/helm-charts/blob/provider-4.3.7/charts/akash-provider/scripts/init.sh#L116.

However, there is a potential issue where a worker node may cache an already expired certificate. The expired certificate would be stored at ~root/.akash/k8s-config/provider.pem on the worker node. This becomes especially problematic when there are multiple worker nodes where the akash-provider pod could be deployed.

Therefore, it's advisable to also check for certificate expiration locally.

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The workaround until then would be:

1. remove the provider cert on all worker nodes:

rm -vf ~root/.akash/k8s-config/provider.pem

2. bounce the provider pod:

kubectl -n akash-services delete pods -l app=akash-provider

[andy108369]

done in #260