Request: option to disable mounts.

Hi folks, I had a situation in which the mount broke my pipeline. I'm currently doing a read only bind of ~/.ssh and mounting a volume that is used for storing the cli history... when I try to build it in AzDO it fails saying that there is no .ssh ... that is expected ... is there a way to disable mounts?

Saw it was including in issue #30

```bash
docker: Error response from daemon: invalid mount config for type "bind": bind source path does not exist: /home/vsts/.ssh.
```
Can't see this [line](https://github.com/devcontainers/ci/blob/afa58a5848bbf08f67d2a6be8935cf8121802362/common/src/docker.ts#L286) in the logs.

cheers,

Juan

Commencez dans common/src/docker.ts autour de la ligne 286 et examinez comment les montages sont transmis lors des builds Azure DevOps. Vérifiez comment les montages bind et volume existants sont configurés, puis définissez et vérifiez une option qui les désactive afin qu’un chemin ~/.ssh manquant ne fasse pas échouer le build.

Rédigé par le modèle d'indexation à partir du texte de l'issue.