cmd/syncthing/cli: Update recli, fix stdin handling (fixes #7685, fixes #7673) (#7694)

go.mod

@@ -2,7 +2,7 @@ module github.com/syncthing/syncthing
 
 require (
 	github.com/AudriusButkevicius/pfilter v0.0.0-20210511165305-e9aaf99ab213
-	github.com/AudriusButkevicius/recli v0.0.5
+	github.com/AudriusButkevicius/recli v0.0.6
 	github.com/alecthomas/kong v0.2.16
 	github.com/bkaradzic/go-lz4 v0.0.0-20160924222819-7224d8d8f27e
 	github.com/calmh/xdr v1.1.0
@@ -30,7 +30,6 @@ require (
 	github.com/lib/pq v1.10.1
 	github.com/lucas-clemente/quic-go v0.19.3
 	github.com/maruel/panicparse v1.6.1
-	github.com/mattn/go-isatty v0.0.12
 	github.com/maxbrunsfeld/counterfeiter/v6 v6.3.0
 	github.com/minio/sha256-simd v1.0.0
 	github.com/miscreant/miscreant.go v0.0.0-20200214223636-26d376326b75