scripts: install gnupg deb, pass --yes to apt-get

Fixes #3685
Fixes #3528
Fixes #3649

Change-Id: Ie029fca6cf3d07a77d228e9591ec1c1c828e68af
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f