Skipped tests are not reported as skipped in xUnit output

[adam-fowler]

Is it reproducible with SwiftPM command-line tools: swift build, swift test, swift package etc?

• Confirmed reproduction steps with SwiftPM CLI.

Description

The xUnit file output by swift test --parallel --xunit-output <file> does not report when a test is skipped

Expected behavior

xUnit file has an xml node that indicates the test was skipped

Actual behavior

Instead it reports that the test ran as if it passed

Steps to reproduce

1. In SwiftPM project create test with the first line try XCTSkipIf(true)
2. Run swift test --parallel --xunit-output test.xml
3. Inspect test.xml
   There is no indication in the file that test was skipped

Swift Package Manager version/commit hash

5.9.2

Swift & OS version (output of swift --version ; uname -a)

swift-driver version: 1.87.3 Apple Swift version 5.9.2 (swiftlang-5.9.2.2.56 clang-1500.1.0.2.5)
Target: arm64-apple-macosx14.0
Darwin Adams-MBP-M1-Max.local 23.2.0 Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:18 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6000 arm64