Add env-file option to the optimize command
Add env-file option to the optimize command

The `ctr run` command has the `env-file` option and it is handy. I think it would be nice to have it in the optimizer.

Signed-off-by: Jun Lin Chen <50f3f01caa053693ce619d596e14b0ff3901ab49@mc256.com>

containerd/stargz-snapshotter,containerd/stargz-snapshotter,containerd/stargz-snapshotter,containerd/stargz-snapshotter