Add demo WF for IpPv6 test

.editorconfig

@@ -6,3 +6,6 @@ insert_final_newline = true
 charset = utf-8
 indent_style = space
 indent_size = 4
+
+[*.yml]
+indent_size = 2

.forgejo/workflows/ipv6test.yml

@@ -0,0 +1,14 @@
+---
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+    ipv6:
+        runs-on: docker
+        steps:
+            - run: |
+                  apt update; apt install --yes curl
+                  curl -s -o /dev/null https://ipv6.google.com