zpay32: improve fuzz tests #10987

Job	Run time
cross compilation	15m 45s
cross compilation	15m 45s
check pinned dependencies (google.golang.org/grpc v1.53.0)	6s
check pinned dependencies (google.golang.org/grpc v1.53.0)	6s
check pinned dependencies (github.com/golang/protobuf v1.5.2)	4s
check pinned dependencies (github.com/golang/protobuf v1.5.2)	4s
check commits	4m 23s
check commits	4m 23s
lint code	8m 25s
lint code	8m 25s
check release notes updated	0s
check release notes updated	0s
RPC and mobile compilation check	2m 15s
RPC and mobile compilation check	2m 15s
sample configuration check	35s
sample configuration check	35s
Sqlc check	24s
Sqlc check	24s
run ubuntu itests	0s
run ubuntu itests	0s
run unit tests (btcd unit-cover)	15m 59s
run unit tests (btcd unit-cover)	15m 59s
run unit tests (unit tags="kvdb_etcd")	19m 4s
run unit tests (unit tags="kvdb_etcd")	19m 4s
run unit tests (unit tags="kvdb_postgres")	16m 14s
run unit tests (unit tags="kvdb_postgres")	15m 57s
run unit tests (unit tags="kvdb_sqlite")	16m 21s
run unit tests (unit tags="kvdb_sqlite")	16m 21s
run unit tests (btcd unit-race)	31m 16s
run unit tests (btcd unit-race)	31m 16s
run windows itest	0s
run windows itest	0s
	4h 21m 25s

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