fix(tahiry29): replace URL redirect with A record + add Vercel verification

Remove the "URL" record that 301-redirects tahiry29.is-a.dev to
tahiry-dev.vercel.app. Add an A record pointing to 216.198.79.1
(Vercel production). Add _vercel.tahiry29.json with the Vercel
domain-ownership TXT (vc-domain-verify=tahiry29.is-a.dev,518fad0fd08d347cdbe0)
so the domain can be moved to this Vercel project.

After this PR merges, tahiry29.is-a.dev will resolve directly to the
Vercel deployment. Vercel will then 308-redirect tahiry-dev.vercel.app
to tahiry29.is-a.dev, making the is-a.dev URL the canonical one.

domains/_vercel.tahiry29.json

@@ -4,6 +4,6 @@
     "email": "tahirydev29@gmail.com"
   },
   "records": {
-    "TXT": "vc-domain-verify=civicballot.tahiry29.is-a.dev,64ea8ca86e5ac8ff8979"
+    "TXT": "vc-domain-verify=tahiry29.is-a.dev,518fad0fd08d347cdbe0"
   }
 }

domains/tahiry29.json

@@ -4,6 +4,6 @@
     "email": "tahirydev29@gmail.com"
   },
   "records": {
-    "URL": "https://tahiry-dev.vercel.app/"
+    "A": ["216.198.79.1"]
   }
 }