autoscaler: Allow customization of taskscaler and fleeting parameters in config.toml
Description
Both taskscaler and fleeting have internal configuration options that are not currently exposed to users for customization.
Proposal
Expose internal configuration parameters such as DeletionRetryInterval, FailureThreshold, ShutdownDeletionInterval, and ShutdownDeletionRetries as configurable options in config.toml.
This would allow administrators to fine-tune these values based on their specific needs or infrastructure requirements.