[FEA] See if we can avoid the warning about leaking HCV used to store GPU Timezone Database

[NVnavkumar]

See #1553 (comment)

Since the HCV is kept around for the entire duration of the executor process, when the executor stops (either normally or by failure), we are not always in a situation whether GpuTimeZoneDB.shutdown() is called at the end. Therefore, we need to suppress the warnings that will come from this part of the code when the host column vector is leaked.