[Error]: distrobox rm ignores `container_name_default` from `~/.distroboxrc`

**Describe the bug**
When using `container_name_default` in `~/.distroboxrc`, the value is respected by `distrobox create` and `distrobox enter`, but not by `distrobox rm`, which uses an incorrect container name.

**To Reproduce**
1. Configure `~/.distroboxrc` with:
```bash
container_name_default="dev"
```
2. Run:
```bash
distrobox create
```
The container is created with the correct default name (`dev`).

3. Run:
```bash
distrobox enter
```
The command enters the correct container (`dev`).

4. Run:
```bash
distrobox rm
```
The prompt shows:
```text
Do you really want to delete containers: my-distrobox? [Y/n]:
```
This uses the wrong container name instead of the configured default.

**Expected behavior**
`distrobox rm` should use the same `container_name_default` value defined in `~/.distroboxrc`, consistently with `distrobox create` and `distrobox enter`.

**Logs**
Not attached yet.

**Desktop (please complete the following information):**
- Are you using podman, docker or lilipod?
- podman
- Which version of podman, docker or lilipod?
- podman 5.8.2
- Which version of distrobox?
- 1.8.2.4
- Which host distribution?
- Fedora Linux 44.20260507.0 (Kinoite)
- How did you install distrobox?
- `rpm-ostree install distrobox`

**Additional context**
This seems to affect only `distrobox rm`. Other commands such as `distrobox create` and `distrobox enter` correctly respect the value set in `~/.distroboxrc`.