ChainDB q-s-m: remove references to in-future blocks

The notion of blocks from the future has been completely eliminated from the
ChainDB in #1269, so
remove any stale (implicit) references.

Author: amesgen

ouroboros-consensus/test/storage-test/Test/Ouroboros/Storage/ChainDB/Model.hs

@@ -842,14 +842,7 @@ validate cfg Model{initLedger, invalid} chain =
           ledger
           (invalid <> mkInvalid b e)
       -- Valid block according to the ledger
-      Right ledger'
-        -- But the block has been recorded as an invalid block. It must be
-        -- that it exceeded the clock skew in the past.
-        | Map.member (blockHash b) invalid ->
-            ValidatedChain validPrefix ledger invalid
-        -- This is the good path
-        | otherwise ->
-            go (convertMapKind ledger') (validPrefix :> b) bs'
+      Right ledger' -> go (convertMapKind ledger') (validPrefix :> b) bs'
 
 chains ::
   forall blk.

ouroboros-consensus/test/storage-test/Test/Ouroboros/Storage/ChainDB/StateMachine.hs

@@ -25,7 +25,6 @@
 -- These are the main tests for the chain DB. Commands include
 --
 -- * Add a block
--- * Add a block with a @SlotNo@ that is ahead of the wall-clock.
 -- * Get the current chain and/or ledger state
 -- * Create a new iterator and use it to stream blocks
 -- * Create a new follower and use it to follow the chain
@@ -178,9 +177,7 @@ import Test.Util.WithEq
 
 -- | Commands
 data Cmd blk it flr
-  = -- | Advance the current slot to the block's slot (unless smaller than the
-    -- current slot), add the block and run chain selection.
-    AddBlock blk
+  = AddBlock blk
   | GetCurrentChain
   | GetTipBlock
   | GetTipHeader