The all_datadirs keeps paths to directories where local sstables can be. In fact, Scylla doesn't put sstables there, but can try to find them on boot and when checking snapshots. The 0th element of this vector, called datadir, had recently been removed by #20675, now it's time to drop all_datadirs as well. The needed paths can be obtained from table's storage options (see #20542) and db::config::data_file_directories option.
Closesscylladb/scylladb#21212
* github.com:scylladb/scylladb:
sstables: Open-code format_table_directory_name() moved recently
replica,sstables: Move format_table_directory_name()
table: Remove all_datadirs
sstables: Generate table::all_datadirs from db::config and storage_options
replica: Prepare vector of fs::path-s with table dirs
table: Check storage options in get_snapshot_details()
ec543e3902