[bitnami/mlflow] Add support for generic ephemeral volume

[kimminw00]

Description of the change

This change introduces a new feature to configure the /tmp volume as a generic ephemeral volume, which is backed by a PersistentVolumeClaim (PVC).

Benefits

Better Resource Management: Administrators can now manage the storage for /tmp using standard Kubernetes storage mechanisms. This allows for applying storage quotas, using specific performance tiers via StorageClass, and isolating /tmp storage from the node's ephemeral disk.

Increased Flexibility: Users can customize the storage characteristics for /tmp by defining their own volumeClaimTemplate, specifying properties like storage size (resources.requests.storage), accessModes, and storageClassName.

Applicable issues

• fixes [MLflow] Allow /tmp directory to use configurable volume instead of ephemeral storage #36283

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)

[kimminw00]

@carrodher Please review this PR when you get a chance.

[juan131]

LGTM