Make sure swift_import propagates the .swiftinterface file in its…

… `SwiftInfo` if it's given one as an input.

PiperOrigin-RevId: 618250957

swift/swift_import.bzl

@@ -116,6 +116,7 @@ def _swift_import_impl(ctx):
             ),
             swift = create_swift_module_inputs(
                 swiftdoc = swiftdoc,
+                swiftinterface = swiftinterface,
                 swiftmodule = swiftmodule,
             ),
         )