A user reported in the IRC chan that installing packages fails with
```
2023-12-13 20:02:34 [INFO] Installing thelounge-theme-solarized v1.1.9...
undefined:1
(node:3329) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
^
SyntaxError: Unexpected token '(', "(node:3329"... is not valid JSON
```
Now, this happens as yarn helpfully prints a deprecation warning
that is shown in the stack trace.
Let's assume that we may get non json messages and log them at debug, as we
don't know their severity.