Cannot get terminal window size inside toolbox via TIOCGWINSZ ioctl

**Describe the bug**
Getting the terminal window size via TIOCGWINSZ ioctl doesn't work inside a toolbox.

**Steps how to reproduce the behaviour**
1. [Install the kitty terminal emulator](https://sw.kovidgoyal.net/kitty/binary/#binary-install) in a user directory, e.g. `~/.local/kitty.app`
2. Open a kitty window, e.g. by executing `~/.local/kitty.app/bin/kitty`
3. Inside kitty, run `infocmp -a > xterm-kitty` to save terminal capabilities
4. Create and enter a toolbox: `toolbox create && toolbox enter`; there should be a warning about unknown terminal type `xterm-kitty`
5. Install the kitty terminal info: `sudo mv xterm-kitty /usr/share/terminfo/x/ && sudo chown root:root /usr/share/terminfo/x/xterm-kitty`
6. Leave the toolbox
7. Run [this Python snippet](https://sw.kovidgoyal.net/kitty/graphics-protocol/#getting-the-window-size) to fetch the terminal window size via ioctl; note the output
8. Enter the toolbox while ensuring kitty integration: `toolbox run ~/.local/kitty.app/bin/kitten run-shell`
9. Run the same Python snippet again and note the output

**Expected behaviour**
Outside the toolbox:
```
number of rows: 40 number of columns: 160screen width: 1440 screen height: 760
```
Inside the toolbox:
```
number of rows: 40 number of columns: 160screen width: 1440 screen height: 760
```
Same output both outside and inside the toolbox.

**Actual behaviour**
Outside the toolbox:
```
number of rows: 40 number of columns: 160screen width: 1440 screen height: 760
```
Inside the toolbox:
```
number of rows: 40 number of columns: 160screen width: 32765 screen height: 0
```
The window size inside the toolbox is different and obviously invalid.

**Output of `toolbox --version` (v0.0.90+)**
`toolbox version 0.0.99.5`

**Toolbx package info (`rpm -q toolbox`)**
`toolbox-0.0.99.5-11.fc40.x86_64`

**Output of `podman version`**
```
Client: Podman Engine
Version: 5.1.2
API Version: 5.1.2
Go Version: go1.22.5
Built: Wed Jul 10 02:00:00 2024
OS/Arch: linux/amd64
```

**Podman package info (`rpm -q podman`)**
`podman-5.1.2-1.fc40.x86_64`

**Info about your OS**
Fedora Silverblue 40

**Additional context**
Output of `toolbox list -i`:
```
IMAGE ID IMAGE NAME CREATED
649e13d69576 registry.fedoraproject.org/fedora-toolbox:40 7 weeks ago
```
Output of `kitty --version`:
```
kitty 0.35.2 created by Kovid Goyal
```

I've logged onto another computer via `kitten ssh` and run the Python snippet there and it found the terminal window size without issue. Running pure `kitten run-shell` without a toolbox also doesn't block terminal window size from being reported.

Please let me know if I forgot any info, thanks in advance!