add --force-delete to ./run

Excluded files in folders were preventing stale folders from being
removed when deps were updated, leading to warnings on run.

run

@@ -11,7 +11,7 @@ run_mac() {
     # so we need to copy the files into a working folder before running on a Mac.
     workspace=$(dirname $0)
     bazel build $BUILDARGS //qt:runanki && \
-        rsync -aiL --exclude=anki/external --exclude=__pycache__ --delete \
+        rsync -aiL --exclude=anki/external --exclude=__pycache__ --delete --force-delete \
             $workspace/bazel-bin/qt/runanki* $workspace/bazel-copy/ && \
         $workspace/bazel-copy/runanki $*
 }