platform-ios's crash diagnostics test fails on Windows because it expects forward slashes #261

Describe the bug

On Windows, packages/platform-ios/src/__tests__/crash-diagnostics.test.ts fails. The test builds the crash report directory with path.join(sourceRoot, '.harness', 'crash-reports'), so the artifact path uses backslashes, but it then checks for the POSIX form:

expect(artifacts[0]?.artifactPath).toContain('/.harness/crash-reports/');

On Windows the path contains \.harness\crash-reports\, so the assertion fails. The pre-push hook runs this test (#241), so pushing from a Windows machine fails.

This was reported after #242 made the iOS package's tests run: #242 (comment).

System Info

System:
  OS: Windows 11

React Native Harness Version

main after #242

Reproduction

https://github.com/callstackincubator/react-native-harness/blob/main/packages/platform-ios/src/__tests__/crash-diagnostics.test.ts

Steps to reproduce

1. On Windows, run pnpm nx test platform-ios.
2. The crash diagnostics test fails on the '/.harness/crash-reports/' assertion.

Part of #247.