fix ImplicitTemplateRedefinition warning

[tersec]

Otherwise it spams the build with:

nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(29, 20) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(85, 10) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(56, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(29, 20) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(85, 10) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(56, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(90, 6) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(149, 10) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(122, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(90, 6) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(149, 10) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/attestation_service.nim(122, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(33, 6) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(92, 3) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(59, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(33, 6) template/generic instantiation of `async` from here
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(92, 3) template/generic instantiation of `setResult` from here
nimbus-eth2/beacon_chain/validator_client/sync_committee_service.nim(59, 3) template/generic instantiation of `logScope` from here
nimbus-eth2/vendor/nim-chronicles/chronicles.nim(74, 14) Warning: template 'activeChroniclesScope' is implicitly redefined; this is deprecated, add an explicit .redefine pragma [ImplicitTemplateRedefinition]

et cetera