add push raises to tests; rm unused test code (#5948)

tests/consensus_spec/test_fixture_fork_choice.nim

@@ -83,11 +83,6 @@ proc initialLoad(
       path/"anchor_block.ssz_snappy",
       SSZ, BlockType)
 
-    signedBlock = ForkedSignedBeaconBlock.init(BlockType.kind.SignedBeaconBlock(
-      message: blck,
-      # signature: - unused as it's trusted
-      root: hash_tree_root(blck)))
-
   ChainDAGRef.preInit(db, forkedState[])
 
   let

tests/consensus_spec/test_fixture_sanity_blocks.nim

@@ -5,6 +5,7 @@
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
+{.push raises: [].}
 {.used.}
 
 import