In Nim 2.0, the `test_fixture_operations` files fail to compile with:
```
Error: 'result' is of type <Result[system.void, system.cstring]> which cannot be captured as it would violate memory safety, declared here: /nimbus-eth2/tests/consensus_spec/bellatrix/test_fixture_operations.nim(130, 5); using '-d:nimNoLentIterators' helps in some cases. Consider using a <ref Result[system.void, system.cstring]> which can be captured.
```
Wrapping the `applyExecutionPayload` in a factory that takes `path`
avoids this problem.
Suite names were not being used because `test` has to have access to it
during instantiation - this PR cleans things up a little while at the
same time upgrading unittest2.
This PR removes a few hundred thousand temporary seq allocations during
state transition - in particular, the flag seq was allocated per
validator while committees are computed per attestation.
* require sync committee supermajority in CI
To better catch problems with sync committee messages in CI, extend
local testnet simulation to also verify that each block is signed
by a supermajority of the sync committee.
Requires #5083 and #5084
* lint
Etan Kissling
tersec
Jacek Sieka
henridf