`eas credentials` does not support unicode properly when creating a certificate

### Build/Submit details page URL

_No response_

### Summary

When creating a new Distribution Certificate via `eas credentials`, if the name contains diacritics or other unicode characters, they end up mangled:

### Managed or bare?

managed

### Environment

```
expo-env-info 2.0.12 environment info:
System:
OS: macOS 15.7.4
Shell: 5.9 - /bin/zsh
Binaries:
Node: 24.14.0 - ~/.asdf/installs/nodejs/24.14.0/bin/node
Yarn: 1.22.22 - ~/.asdf/installs/nodejs/24.14.0/bin/yarn
npm: 11.9.0 - ~/.asdf/plugins/nodejs/shims/npm
SDKs:
iOS SDK:
Platforms: DriverKit 25.2, iOS 26.2, macOS 26.2, tvOS 26.2, visionOS 26.2, watchOS 26.2
Android SDK:
API Levels: 33, 33, 34
Build Tools: 30.0.3, 33.0.0, 33.0.2, 34.0.0, 34.0.0, 36.1.0
System Images: android-33 | Google APIs ARM 64 v8a, android-34 | Google APIs ARM 64 v8a, android-34 | Google Play ARM 64 v8a, android-36 | Google APIs ARM 64 v8a, android-36 | Google Play ARM 64 v8a
IDEs:
Android Studio: 2025.3 AI-253.31033.145.2533.15176040
Xcode: 26.3/17C529 - /usr/bin/xcodebuild
npmPackages:
@expo/webpack-config: ~19.0.1 => 19.0.1
babel-preset-expo: ~13.0.0 => 13.0.0
expo: ^53.0.0 => 53.0.27
expo-updates: ~0.28.18 => 0.28.18
react: 19.0.0 => 19.0.0
react-dom: 19.0.0 => 19.0.0
react-native: 0.79.6 => 0.79.6
react-native-web: ^0.20.0 => 0.20.0
npmGlobalPackages:
eas-cli: 18.7.0
Expo Workflow: managed
```

### Error output

_No response_

### Reproducible demo or steps to reproduce from a blank project

1. Find someone with non-English name and an Apple account
2. Ask them to create a new distribution certificate via `eas credentials`