[FLINK-29694] Support tolerations in helm template for flink operator deployment

[zhiminglim]

What is the purpose of the change

Support for tolerations in helm chart to allow operator pod to tolerate nodes with taints

Brief change log

• Add tolerations in operator deployment manifest

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Tested with helm template to ensure tolerations is added to the operator's deploymentSpec when tolerations is set in the values.yaml file

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changes to the CustomResourceDescriptors: no
• Core observer or reconciler logic that is regularly executed: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable