Add support for user-defined labels on the Pulp Operator pod

[ismaildem]

Is your feature request related to a problem? Please describe.
The Pulp Operator does not currently provide a way to configure custom Kubernetes labels on the operator pod itself.
This is a limitation when integrating the operator into clusters that rely on labels for security policies.

Describe the solution you'd like
Provide a supported mechanism to configure custom labels for the Pulp Operator pod, for example via the operator’s Helm chart values.

Describe alternatives you've considered
Manually editing the operator Deployment to add labels, which is overwritten during upgrades or reinstallation.
Using cluster-wide mutating admission webhooks to inject labels, which adds unnecessary complexity and is not specific to the Pulp Operator.