Decide what to do with remaining mentions of Grand filesystem

[felker]

see https://github.com/argonne-lcf/user-guides/pull/591/files#r1907996664

and #475, #505

❯ grep -nri "grand" .
./data-management/filesystem-and-storage/disk-quota.md:17:The amount of data stored under `/lus/grand/projects/PROJECT_NAME` cannot exceed the approved project quota limit approved during the allocation period. The total data usage under the project directory is used to calculate the disk quota.
./data-management/data-transfer/using-globus.md:11:Several data transfer nodes (DTNs) for `/home`, Eagle, Grand, and HPSS are available to ALCF users, allowing users to perform wide and local area data transfers. Access to the DTNs is provided via the following Globus endpoints.
./data-management/data-transfer/using-globus.md:19:- Grand filesystem: `alcf#dtn_grand` for accessing `/lus/grand/projects` or `/grand` (i.e. project directories on Grand filesystem). Use the path `/grand/<project name\>`
./sophia/visualization/serverfiles/sophia.pvsc:42:          <String default="home:eagle:grand"/>
./sophia/visualization/serverfiles/windowsToSophia.pvsc:42:          <String default="home:eagle:grand"/>

While the fate of Grand is unclear, it seems like the visualization .pvsc files should at least be updated to remove the mountpoint, but also the appearance in disk-quota.md?