Cabal unusable in Windows when username has unicode characters

**Describe the bug**
Cabal becomes unusable in Windows when the username has unicode characters (that is my suspicion), because attempts to read e.g. the global config fail.

**To Reproduce**
```
Daniel João@DESKTOP-PBTBE76 MINGW64 /tmp/tmp.UvhafQVlZ0/ghc
$ cabal --store-dir=$(pwd)/store install alex-3.5.0.0 happy --installdir=$(pwd)/bin
Config file path source is default config file.
Config file not found: C:\Users\Daniel Jo?o\AppData\Roaming\cabal\config
Writing default configuration to C:\Users\Daniel
Jo?o\AppData\Roaming\cabal\config
C:\Users\Daniel Jo?o\AppData\Roaming\cabal\config.tmp: withFile: invalid argument (invalid character)
```

**System information**
- Operating system: Windows Mingw-w64-x86_64
- `cabal`, `ghc` versions: ghc 9.8.2, cabal 3.10.3