Backport disks mount point clarifications to WDL 1.1 #756
Description
The semantics for disks mount points were clarified in WDL 1.2 via commits 072fcd7 and 1c69180. These changes clarified that:
- Mount points are in the execution environment (i.e., within the container), not the host
- Mount points must not already exist or must be empty
- Mount points are ephemeral (deleted after task completes)
This issue tracks backporting these clarifications to WDL 1.1.4.
Related: #672