Allow creation of SBOM in ACR by using 'docker sbom'

**What is the problem you're trying to solve**
We use ACR to build our images in our CI pipeline. Additionally, we want to generate SBOM files.
We tried to execute the following command:

```
az acr run --registry myregistry --cmd 'docker sbom myimage' /dev/null
```

However, we get an error:

```
2023/12/19 15:18:53 Executing step ID: acb_step_0. Timeout(sec): 600, Working directory: '', Network: 'acb_default_network'
2023/12/19 15:18:53 Launching container with name: acb_step_0
/usr/local/bin/docker-entrypoint.sh: line 20: exec: sbom: not found
```

**Describe the solution you'd like**
It would be nice to be able to create SBOM from images in the ACR without the need to pull them.

**Additional context**
Other commands like 'docker inspect' work flawlessly.