Add option to add additional labels to lakefs pod

[wadhah101]

In certain cases you want to override the pod labels.
example : adding azure.workload.identity/use=true in https://learn.microsoft.com/en-us/azure/aks/workload-identity-overview?tabs=dotnet#pod-labels

this pr adds the option to specify labels

[CLAassistant]

All committers have signed the CLA.

[N-o-Z]

@wadhah101 thank you for opening this PR!
Can you please add a short description in the PR explaining the change and the reason for the request.

[wadhah101]

@wadhah101 added description

[Isan-Rivkin]

Thanks for drafting this. Please bump Chart.yaml

[wadhah101]

@Isan-Rivkin Bumped to 1.3.26

[Isan-Rivkin]

First, thanks for drafting this PR!

The issue with this change is that K8S does not allow duplicate keys in labels.
Add a duplicate key such as app to podLabels yourself you'll see.
For me it breaks when I add podLabel app=duplicate I run helm install with the error

The Deployment "lakefs" is invalid: spec.template.metadata.labels: Invalid value: map[string]string{"app":"duplicate", "app.kubernetes.io/instance":"lakefs", "app.kubernetes.io/name":"lakefs"}: `selector` does not match template `labels`

kubectl version (on EKS):

Client Version: v1.29.0
Server Version: v1.30.7

So first, can you please better explain your use-case, is it specifically pod labels or Deployment labels? is it specifically override specific label keys? Should this affect the labelSelector?
What is it you would like to achieve.

Second incase of override label keys, I'd go with an override all-or-nothing approach not appending to existing labels.