feat(infra): Add checks for meta

.forgejo/workflows/check-meta.yaml

@@ -0,0 +1,22 @@
+name: Check meta
+on:
+  push:
+    paths:
+      - 'meta/*'
+
+jobs:
+  check_meta:
+    runs-on: nix
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Check the validity of meta options
+        run: nix-build meta/verify.nix -A meta
+
+  check_dns:
+    runs-on: nix
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Check the validity of the DNS configuration
+        run: nix-build meta/verify.nix -A dns --no-out-link