The CI job "Test / Windows (5.9 - windows-2022)" always fails

[kkebo]

The CI job "Test / Windows (5.9 - windows-2022)" always fails on both swiftlang/swift-format and forks with the following error:

[335/23685] Fetching swift-argument-parser, swift-markdown
Fetched https://github.com/swiftlang/swift-markdown.git (1.16s)
Computing version for https://github.com/swiftlang/swift-markdown.git
Computed https://github.com/swiftlang/swift-markdown.git at 0.7.1 (0.95s)
Creating working copy for https://github.com/swiftlang/swift-markdown.git
Working copy of https://github.com/swiftlang/swift-markdown.git resolved at 0.7.1
error: 'source': the target 'Markdown' in product 'Markdown' contains unsafe build flags
error: 'source': the target 'Markdown' in product 'Markdown' contains unsafe build flags

Full logs:

• https://github.com/swiftlang/swift-format/actions/runs/19373620734/job/55435469761
• https://github.com/swiftlang/swift-format/actions/runs/19373443594/job/55434868971
• https://github.com/swiftlang/swift-format/actions/runs/19346926084/job/55349536784
• https://github.com/kkebo/swift-format/actions/runs/19387913705/job/55477413199?pr=619

Related issues:

• unsafeFlags introduced in Markdown 0.7.0 causes SwiftPM dependency resolution failures swift-markdown#239