Beat itest [3/3]: fix all itest flakes #16847

Job	Run time
cross compilation	31m 12s
check pinned dependencies (google.golang.org/grpc v1.59.0)	9s
basic itests (btcd, backend=btcd cover=1)	13m 36s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	3s
check commits	17m 34s
basic itests (bitcoind, backend=bitcoind cover=1)	16m 2s
basic itests (bitcoind-notxindex, backend="bitcoind notxindex")	15m 20s
itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling")	26m 23s
macOS itest	16m 56s
basic itests (neutrino, backend=neutrino cover=1)	12m 55s
itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	28m 9s
lint code	6m 42s
itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	24m 41s
itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	23m 10s
check release notes updated	5s
itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	39m 31s
RPC and mobile compilation check	3m 35s
sample configuration check	1m 47s
Sqlc check	2m 39s
itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	40m 31s
run unit tests (btcd unit-cover)	19m 13s
windows itest	34m 38s
run unit tests (unit tags="kvdb_etcd")	20m 21s
run unit tests (unit tags="kvdb_postgres")	19m 51s
run unit tests (unit tags="kvdb_sqlite")	18m 47s
run unit tests (btcd unit-race)	39m 53s
run unit tests (unit-module)	1m 1s
finish	6s
	7h 54m 50s

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