ci: TestDynamicOffChainCensus failed with `could not load census: census not found in the local database`

[altergui]

just seen this in the wild, in a PR totally unrelated to census
https://github.com/vocdoni/davinci-node/actions/runs/20954198034/job/60214665940

2026-01-13T11:07:08.564Z DBG api/errors.go:55 > API error response error="internal server error: could not load census: census not found in the local database: 000ee4f27ae6bac87009f7bb77dd86d090f7b4c09d00e4bf4392be8f63d37321" code=50002 httpStatus=500
2026-01-13T11:07:08.564Z DBG api/middleware.go:141 > api response method=POST status=500 took=2.110357ms url=/votes
    census_test.go:122: 
        error:
          values are not equal
        got:
          int(500)
        want:
          int(200)
        stack:
          /home/github/actions-runner/_work/davinci-node/davinci-node/tests/census_test.go:122
            c.Assert(status, qt.Equals, 200)
        
=== NAME  TestDynamicOffChainCensus
    census_test.go:132: 
        error:
          unexpected length
        len(got):
          int(0)
        got:
          []*big.Int(nil)
        want length:
          int(2)
        stack:
          /home/github/actions-runner/_work/davinci-node/davinci-node/tests/census_test.go:132
            c.Assert(ks, qt.HasLen, numInitialVoters)
        
--- FAIL: TestDynamicOffChainCensus (8.22s)

[altergui]

cc @lucasmenendez

[altergui]

happened again in another run

https://github.com/vocdoni/davinci-node/actions/runs/20963276217/job/60246289902?pr=307

[lucasmenendez]

It should be fixed after #338