"Invalid PNG signature" preventing compilation on Ubuntu

I am trying to compile hackatime-desktop on my Ubuntu system. I have tried both of the following commands:

- `pnpm run tauri build`
- `pnpm tauri dev`

Both times I tried this, I got an error that I will paste below:
```
error: proc macro panicked
--> src/lib.rs:345:14
|
345 | .run(tauri::generate_context!())
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: message: failed to read icon /home/left-alert-chaos/Desktop/hackatime-desktop/src-tauri/icons/32x32.png: Invalid PNG signature.

warning: unused import: `TitleBarStyle`
--> src/lib.rs:3:35
|
3 | use tauri::{Manager, WindowEvent, TitleBarStyle};
| ^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default

warning: `desktop` (lib) generated 1 warning
error: could not compile `desktop` (lib) due to 1 previous error; 1 warning emitted
failed to build app: failed to build app
Error failed to build app: failed to build app
 ELIFECYCLE  Command failed with exit code 1.
```

Start by inspecting src-tauri/icons/32x32.png and reproducing the failure with `pnpm run tauri build` or `pnpm tauri dev`. Check the icon's PNG validity and then confirm that the build proceeds past `tauri::generate_context!()` without the invalid-signature error.

Written by the indexing model from the issue text.