os: Update caddy to fix / endpoint

fairscope/PlanktoScope3#529

Author: sonnyp

os/caddy/justfile

@@ -1,4 +1,9 @@
 setup:
+    curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
+    curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
+    sudo chmod o+r /usr/share/keyrings/caddy-stable-archive-keyring.gpg
+    sudo chmod o+r /etc/apt/sources.list.d/caddy-stable.list
+    sudo apt update
     sudo apt install -y caddy
     sudo cp Caddyfile /etc/caddy/
     sudo systemctl reenable caddy