add support for podman chown volume mounting option

[COC-Compliant]

Podman supports a chown mounting feature ":U" that greatly simplifies running rootless containers. When trying to generate a quadlet I get the following error. Would you be willing to add support for this feature?

podlet compose compose.yaml 
Error: 
   0: error converting compose file
   1: error reading compose file
   2: File `compose.yaml` is not a valid compose file
   3: services.test.volumes[0]: unknown volume option `U` at line 7 column 9

Location:
   src/cli/compose.rs:203

Example compose.yaml

services:
  test:
    image: docker.io/alpine:latest
    user: 42
    volumes:
      - ./test:/test:U

Sidenote: volume mounting is broken in some crun versions, use stable (1.21) or latest (1.24+)