Scanning Swift code doesn't work when building with Xcode 16

[bwhtmn]

Running a CodeQL scan on Swift code using a manual build fails, when building with Xcode 16.0 with the following error message:

CodeQL detected code written in Swift but this run didn't build any of it, or CodeQL could not process any of it. Ensure that you have provided manual build steps (see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages#about-specifying-build-steps-manually) for Swift between the 'init' and 'analyze' Actions, and check the workflow run logs (see https://docs.github.com/en/actions/monitoring-and-troubleshooting-workflows/using-workflow-run-logs). For more information, review our troubleshooting guide at https://gh.io/troubleshooting-code-scanning/no-source-code-seen-during-build .

Building with Xcode 15.4 doesn't have this issue. I've reproduced this with a basic sample app (just using the new app template from Xcode) to verify that it's not specific to our app configuration.