Packager: Move commands that can fail to post script

bin/release-_post.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 set -e
 
+npm run update-authors
 git diff --exit-code
 npm run package -- --sign
 git push

bin/release-_pre.sh

@@ -2,8 +2,6 @@
 set -e
 
 git pull
-npm run update-authors
-git diff --exit-code
 rm -rf node_modules/
 npm install
 npm dedupe