Cannot compile simulators with '-d:nimbus_db_backend:none'

[jangko]

Hive simulators failed to compile with this error message:

$\nimbus-eth1\nimbus\sync\snap\worker\db\snapdb_desc.nim(37, 12) Error: undeclared identifier: 'RocksStoreRef'
candidates (edit distance, scope distance); see '--spellSuggest':
 (1, 2): 'rocksStoreRef' [proc declared in $\nimbus-eth1\nimbus\sync\snap\worker\db\rocky_bulk_load.nim(102, 6)]

Reason:
Hive simulators is build using -d:nimbus_db_backend:none, therefore it doesn't care about underlying persistent db and only use in memory db.

ping @mjfh

[jangko]

fixed, closing