Beat itest [3/3]: fix all itest flakes #16872

Job	Run time
RPC and mobile compilation check	3m 23s
check commits	16m 48s
Sqlc check	2m 40s
basic itests (btcd, backend=btcd cover=1)	15m 26s
cross compilation	31m 15s
sample configuration check	1m 55s
basic itests (bitcoind, backend=bitcoind cover=1)	15m 31s
lint code	6m 50s
basic itests (bitcoind-notxindex, backend="bitcoind notxindex")	13m 33s
basic itests (neutrino, backend=neutrino cover=1)	14m 46s
run unit tests (btcd unit-cover)	19m 23s
run unit tests (unit tags="kvdb_etcd")	20m 36s
check pinned dependencies (google.golang.org/grpc v1.59.0)	5s
run unit tests (unit tags="kvdb_postgres")	19m 47s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	5s
itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling")	26m 22s
run unit tests (unit tags="kvdb_sqlite")	18m 23s
itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	29m 56s
run unit tests (btcd unit-race)	39m 51s
itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	23m 55s
macOS itest	21m 28s
itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	24m 23s
run unit tests (unit-module)	1m 2s
itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	44m 55s
check release notes updated	4s
itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	38m 33s
windows itest	39m 26s
finish	10s
	8h 10m 31s

Provide feedback