Beat itest [3/3]: fix all itest flakes #16932

Job	Run time
Sqlc check	2m 42s
check commits	17m 29s
lint code	6m 59s
cross compilation	32m 14s
RPC and mobile compilation check	3m 26s
sample configuration check	1m 47s
run unit tests (btcd unit-cover)	19m 20s
run unit tests (unit tags="kvdb_etcd")	20m 28s
basic itests (btcd, backend=btcd cover=1)	15m 32s
check pinned dependencies (google.golang.org/grpc v1.59.0)	3s
run unit tests (unit tags="kvdb_postgres")	19m 39s
basic itests (bitcoind, backend=bitcoind cover=1)	15m 31s
check pinned dependencies (github.com/golang/protobuf v1.5.3)	3s
run unit tests (unit tags="kvdb_sqlite")	17m 57s
basic itests (bitcoind-notxindex, backend="bitcoind notxindex")	13m 41s
run unit tests (btcd unit-race)	39m 56s
basic itests (neutrino, backend=neutrino cover=1)	12m 33s
run unit tests (unit-module)	1m 6s
itests (bitcoind-rpcpolling, backend="bitcoind rpcpolling")	24m 55s
itests (bitcoind-etcd, backend=bitcoind dbbackend=etcd)	28m 27s
macOS itest	18m 21s
itests (bitcoind-sqlite, backend=bitcoind dbbackend=sqlite)	23m 42s
check release notes updated	5s
itests (bitcoind-sqlite-nativesql, backend=bitcoind dbbackend=sqlite nativesql=true)	23m 4s
windows itest	34m 47s
itests (bitcoind-postgres, backend=bitcoind dbbackend=postgres)	40m 25s
itests (bitcoind-postgres-nativesql, backend=bitcoind dbbackend=postgres nativesql=true)	40m 7s
finish	3s
	7h 54m 22s

Provide feedback