Remove isOpen from LedgerTablesHandle (#1461)

It is unused

Author: jorisdral

ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Storage/LedgerDB/V2/InMemory.hs

@@ -121,11 +121,6 @@ newInMemoryLedgerTablesHandle someFS@(SomeHasFS hasFS) l = do
     , tablesSize = do
         hs <- readTVarIO tv
         guardClosed hs (pure . Just . Map.size . getValuesMK . getLedgerTables)
-    , isOpen = do
-        hs <- readTVarIO tv
-        case hs of
-          LedgerTablesHandleOpen{}   -> pure True
-          LedgerTablesHandleClosed{} -> pure False
     }
 
 {-------------------------------------------------------------------------------

ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Storage/LedgerDB/V2/LedgerSeq.hs

@@ -92,7 +92,6 @@ data LedgerTablesHandle m l = LedgerTablesHandle {
     -- | Consult the size of the ledger tables in the database. This will return
     -- 'Nothing' in backends that do not support this operation.
   , tablesSize         :: !(m (Maybe Int))
-  , isOpen             :: !(m Bool)
   }
   deriving NoThunks via OnlyCheckWhnfNamed "LedgerTablesHandle" (LedgerTablesHandle m l)