Fix MEV builder file descriptor leaks.

beacon_chain/nimbus_beacon_node.nim

@@ -710,9 +710,7 @@ proc init*(T: type BeaconNode,
 
   let payloadBuilderRestClient =
     if config.payloadBuilderEnable:
-      RestClientRef.new(
-          config.payloadBuilderUrl,
-          httpFlags = {HttpClientFlag.NewConnectionAlways}).valueOr:
+      RestClientRef.new(config.payloadBuilderUrl).valueOr:
         warn "Payload builder REST client setup failed",
           payloadBuilderUrl = config.payloadBuilderUrl
         nil

beacon_chain/spec/mev/rest_bellatrix_mev_calls.nim

@@ -18,7 +18,7 @@ export chronos, client, rest_types, eth2_rest_serialization
 proc registerValidator*(body: seq[SignedValidatorRegistrationV1]
                        ): RestPlainResponse {.
      rest, endpoint: "/eth/v1/builder/validators",
-     meth: MethodPost.}
+     meth: MethodPost, connection: {Dedicated, Close}.}
   ## https://github.com/ethereum/builder-specs/blob/v0.2.0/apis/builder/validators.yaml
   ## https://github.com/ethereum/beacon-APIs/blob/master/apis/validator/register_validator.yaml
 
@@ -27,16 +27,16 @@ proc getHeader*(slot: Slot,
                 pubkey: ValidatorPubKey
                ): RestResponse[GetHeaderResponse] {.
      rest, endpoint: "/eth/v1/builder/header/{slot}/{parent_hash}/{pubkey}",
-     meth: MethodGet.}
+     meth: MethodGet, connection: {Dedicated, Close}.}
   ## https://github.com/ethereum/builder-specs/blob/v0.2.0/apis/builder/header.yaml
 
 proc submitBlindedBlock*(body: SignedBlindedBeaconBlock
                         ): RestResponse[SubmitBlindedBlockResponse] {.
      rest, endpoint: "/eth/v1/builder/blinded_blocks",
-     meth: MethodPost.}
+     meth: MethodPost, connection: {Dedicated, Close}.}
   ## https://github.com/ethereum/builder-specs/blob/v0.2.0/apis/builder/blinded_blocks.yaml
 
 proc checkBuilderStatus*(): RestPlainResponse {.
      rest, endpoint: "/eth/v1/builder/status",
-     meth: MethodGet.}
+     meth: MethodGet, connection: {Dedicated, Close}.}
   ## https://github.com/ethereum/builder-specs/blob/v0.2.0/apis/builder/status.yaml