build: Specify zeromq port explicitly for MSVC builds

Current port 4 is broken:
- microsoft/vcpkg#22681 (comment)

Author: hebasto

build_msvc/vcpkg.json

@@ -14,5 +14,13 @@
       "features": ["thread"]
     },
     "zeromq"
+  ],
+  "builtin-baseline": "b86c0c35b88e2bf3557ff49dc831689c2f085090",
+  "overrides": [
+    {
+      "name": "zeromq",
+      "version": "4.3.4",
+      "port-version": 3
+    }
   ]
 }