macos-signer-stapler should wait for user interaction before attempting stapling

Now that we only have 1 locale to upload and notarize, the stapling scriptmacos-signer-staplernow fails if run immediately aftermacos-signer-notarization`. Previously, the first bundle would have been notarized by the time stapling had begun so the whole process could work without a pause.

We should add a pause that requires user interaction to proceed once the signer has received the notarization worked email.