feat: prestart detect version

Author: samrose

ansible/files/postgres_prestart.sh.j2

@@ -51,9 +51,9 @@ get_pg_cron_version() {
         return
     fi
 
-    # Run jq as postgres user since it's in their nix profile
+    # Run jq from nixpkgs
     local version
-    version=$(sudo -u postgres /var/lib/postgresql/.nix-profile/bin/jq -r '.pg_cron // empty' "/root/pg_extensions.json")
+    version=$(nix run nixpkgs#jq -- -r '.pg_cron // empty' "/root/pg_extensions.json")
     if [ -z "$version" ]; then
         log "pg_cron: Not specified in extensions file"
         return