Update StashCache client to 6.0.0

Description

StashCache (stashcp) has been updated to v6.0.0.
https://github.com/opensciencegrid/StashCache/releases/tag/v6.0.0

Freshdesk Tickets

None

Assignee

Tim Theisen

Reporter

Derek Weitzel

Priority

Major

Labels

Components

Epic Link

Fix versions

Configure