Store screenshots included in EAS build uploads

### Build/Submit details page URL

_No response_

### Summary

We updated to the latest eas-cli where metadata now includes store screenshots. However, when we make an `eas build` then the screenshots get bundled which makes the archive huge:

```
Compressing project files and uploading to EAS. Learn more
✔ Compressed project files 11s (355 MB)
Your project archive is 355 MB. You can reduce its size and the time it takes to upload by excluding files that are unnecessary for the build process in .easignore file.
```

I think screenshots (and other store metadata) should be excluded by default.

### Managed or bare?

Bare (CNG)

### Environment

18/18 checks passed. No issues detected!

expo-env-info 2.0.12 environment info:
System:
OS: macOS 26.4.1
Shell: 5.9 - /bin/zsh
Binaries:
Node: 24.14.0 - /opt/homebrew/bin/node
npm: 11.9.0 - /opt/homebrew/bin/npm
Managers:
CocoaPods: 1.16.2 - /opt/homebrew/bin/pod
SDKs:
iOS SDK:
Platforms: DriverKit 25.4, iOS 26.4, macOS 26.4, tvOS 26.4, visionOS 26.4, watchOS 26.4
IDEs:
Android Studio: 2025.3 AI-253.30387.90.2532.14935130
Xcode: 26.4.1/17E202 - /usr/bin/xcodebuild
npmPackages:
expo: ~55.0.23 => 55.0.23
expo-router: ~55.0.14 => 55.0.14
expo-updates: ~55.0.21 => 55.0.21
react: 19.2.0 => 19.2.0
react-dom: 19.2.0 => 19.2.0
react-native: 0.83.6 => 0.83.6
react-native-web: ~0.21.2 => 0.21.2
npmGlobalPackages:
eas-cli: 18.12.0
expo-cli: 6.3.12
Expo Workflow: bare

### Error output

_No response_

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

1. Run `eas metadata:pull`
2. Run `eas build`