Remove lingo

lingo-api ran PHP 8.1.34 (php:8.1-apache) and was reachable at
https://lingo.rubenhensen.nl/api/. PHP 8.1 is EOL and gets no fix for
CVE-2026-109618 and CVE-2026-109619, so it was exposed to the PHP2Shell
RCE. It is no longer used, so drop it entirely: the app, its Gatus
check, the DNS record and the node001 tunnel entry.

dns/domains/rubenhensen.nl.yaml

@@ -43,10 +43,6 @@ records:
     expire: 300
     type: A
     content: "46.224.26.65"
-  - name: "lingo"
-    expire: 300
-    type: A
-    content: "46.224.26.65"
   - name: "blog"
     expire: 300
     type: A