A new version of `Microsoft.iOS.Sdk` was released on
2023-05-09T17:28:41.7300000. This version requires Xcode 14.3, which is
not currently available on `macos-latest` runners (which currently alias
to `macos-12`).
To fix, migrate to `macos-13`, which is currently in beta, and
explicitly use Xcode 14.3 (because even on the `macos-13` image, Xcode
14.3 is not yet the default).
- Update the GitHub Actions workflows to their latest versions.
- Replace the usage of the deprecated `set-output` command with the
new recommended way to set the output.
- Format the YAML files.