Update signer to use get_public_key instead of assuming bunker key == user key

watch.sh

@@ -1,7 +1,5 @@
 #!/bin/bash
 
-./build.sh
-
 for package in $(./get_packages.py); do
   npx onchange packages/$package -e '**/build/**' -k -- ./build_and_link.sh $package &
 done