gitserver: rename MigrateFrom to CloneFromShard
Created by: asdine
The MigrateFrom
option is no longer temporary and must be used as an API to copy repos from one shard to another.
This PR renames it to CloneFromShard
and updates some comments.
Related to #32312 (closed)
Test plan
- Breaking change: This option is not used yet so it's safe to rename it
- Relying on the test suite