Add rsync, m4 to the generated images

it's hard to use opam without installing them :)
16 jobs for master
Status Job ID Name Coverage
  .Pre
passed #74161
make-targets

00:00:25

failed #74160
make-targets

00:00:00

failed #74153
make-targets

00:00:00

failed #74152
make-targets

00:00:00

failed #74151
make-targets

00:00:00

failed #74150
make-targets

00:00:00

failed #74149
make-targets

00:00:00

failed #74142
make-targets

00:00:01

failed #74141
make-targets

00:00:00

failed #74140
make-targets

00:00:00

failed #74139
make-targets

00:00:00

failed #74138
make-targets

00:00:01

failed #74134
make-targets

00:00:00

failed #74130
make-targets

00:00:00

failed #74122
make-targets

 
  Build
failed build-images