systemd-oomd kills all processes inside a container

**Describe the bug**

I am using toolbox on silverblue 34 all day to do development inside vscode using [toolbox-vscode](https://github.com/owtaylor/toolbox-vscode/) and the container silently stops and I have to reload the vscode window. I think the issue is totally unrelated to vscode but it is just the way I am running my toolbox.

It looks like the command line of the main toolbox process inside the podman container is `toolbox --verboseinit-container --home /var/home/thiblahute --home-link --media-link --mnt-link --monitor-host --shell /bin/bash --uid 1000 --user thiblahute` and I am using `zsh` as default shell inside the container, I have the impression this process stop which leads to the container stopping but I have no proof of that at this point.

**Steps how to reproduce the behaviour**
1. Use toolbox for a while
2. See that the podman container stops randomly

**Expected behaviour**
I can use toolbox forever without needing to restart it

**Actual behaviour**
The toolbox container stops after a while, a few times a day and I have to restart it.

**Output of `toolbox --version` (v0.0.90+)**

```
toolbox version 0.0.99.1
```

**Toolbox package info (`rpm -q toolbox`)**

```
toolbox-0.0.99.1-1.fc34.x86_64
```

**Output of `podman version`**

```
Version: 3.2.1
API Version: 3.2.1
Go Version: go1.16.3
Built: Mon Jun 14 21:12:29 2021
OS/Arch: linux/amd64
```

**Podman package info (`rpm -q podman`)**
```
podman-3.2.1-1.fc34.x86_64
```

**Info about your OS**

Fedora Silverblue 34