ARM64 support

[BojanZelic]

Have some rasberry pi's I was planning on running this on but the image doesn't have arm64 support. Adding support should be as simple as using docker buildx

docker manifest inspect quay.io/samba.org/samba-operator:v0.4

{
        "schemaVersion": 2,
        "mediaType": "application/vnd.oci.image.manifest.v1+json",
        "config": {
                "mediaType": "application/vnd.oci.image.config.v1+json",
                "digest": "sha256:20295910427b9d52d2e6777585154a630bb7b276306983dc5c77a80d9bab2a11",
                "size": 7632
        },
        "layers": [
                {
                        "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
                        "digest": "sha256:a032f50e22ae11b241fcf38b4a787f0e51009578eedaf9d05894f5f38fd12af5",
                        "size": 37718602
                },
                {
                        "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
                        "digest": "sha256:c9467e3d8012e3d28ef1a251c8f2be9b564344bf155056d7ba2ab89dc8502e86",
                        "size": 23957809
                }
        ],
        "annotations": {
                "org.opencontainers.image.base.digest": "sha256:3e313209ac617a92b50350286752311d99ea2dafc429ef0e5311889294b0bc21",
                "org.opencontainers.image.base.name": "registry.access.redhat.com/ubi9/ubi-minimal:latest"
        }
}