cleanups: `proc` -> `func`, unused import, spec URLs (#4224)

beacon_chain/beacon_chain_db.nim

@@ -563,20 +563,20 @@ proc decodeSZSSZ[T](data: openArray[byte], output: var T): bool =
       err = e.msg, typ = name(T), dataLen = data.len
     false
 
-proc encodeSSZ(v: auto): seq[byte] =
+func encodeSSZ(v: auto): seq[byte] =
   try:
     SSZ.encode(v)
   except IOError as err:
     raiseAssert err.msg
 
-proc encodeSnappySSZ(v: auto): seq[byte] =
+func encodeSnappySSZ(v: auto): seq[byte] =
   try:
     snappy.encode(SSZ.encode(v))
   except CatchableError as err:
     # In-memory encode shouldn't fail!
     raiseAssert err.msg
 
-proc encodeSZSSZ(v: auto): seq[byte] =
+func encodeSZSSZ(v: auto): seq[byte] =
   # https://github.com/google/snappy/blob/main/framing_format.txt
   try:
     encodeFramed(SSZ.encode(v))

beacon_chain/eth1/eth1_monitor.nim

@@ -308,7 +308,7 @@ func voting_period_start_time(state: ForkedHashedBeaconState): uint64 =
   compute_time_at_slot(
     getStateField(state, genesis_time), eth1_voting_period_start_slot)
 
-# https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/validator.md#get_eth1_data
+# https://github.com/ethereum/consensus-specs/blob/v1.2.0/specs/phase0/validator.md#get_eth1_data
 func is_candidate_block(cfg: RuntimeConfig,
                         blk: Eth1Block,
                         period_start: uint64): bool =

beacon_chain/spec/eth2_apis/dynamic_fee_recipients.nim

@@ -2,7 +2,6 @@ import
   std/tables,
   stew/results,
   chronicles,
-  web3/ethtypes,
   ../datatypes/base
 
 type

beacon_chain/validators/validator_duties.nim

@@ -940,7 +940,7 @@ proc handleAttestations(node: BeaconNode, head: BlockRef, slot: Slot) =
   # We need to run attestations exactly for the slot that we're attesting to.
   # In case blocks went missing, this means advancing past the latest block
   # using empty slots as fillers.
-  # https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.1/specs/phase0/validator.md#validator-assignments
+  # https://github.com/ethereum/consensus-specs/blob/v1.2.0/specs/phase0/validator.md#validator-assignments
   let
     epochRef = node.dag.getEpochRef(
       attestationHead.blck, slot.epoch, false).valueOr: