Require rescript v12 and remove usage of Core (#185)

Co-authored-by: Gabriel Nordeborn <gabbe.nord@gmail.com>

Author: tsnobip

.changeset/famous-planes-fetch.md

@@ -0,0 +1,7 @@
+---
+"@rescript-relay-router-example/client-rendering": major
+"@rescript-relay-router-example/express": major
+"rescript-relay-router": major
+---
+
+Require Rescript v12 and remove usage of Core

examples/client-rendering/package.json

@@ -44,7 +44,7 @@
     "react-dom": "^18.2.0",
     "react-relay": "17.0.0",
     "relay-runtime": "17.0.0",
-    "rescript": "11.1.3",
+    "rescript": "12.0.0-alpha.13",
     "rescript-relay": "3.0.0",
     "rollup": "^2",
     "rollup-plugin-visualizer": "5.5.0",
@@ -54,7 +54,6 @@
   },
   "dependencies": {
     "@rescript-relay-router/test-utils": "workspace:^",
-    "@rescript/core": "1.5.2",
     "history": "^5.2.0",
     "jsonc-parser": "^3.0.0",
     "rescript-relay-router": "workspace:^",

examples/client-rendering/rescript.json

@@ -28,10 +28,9 @@
   "bs-dependencies": [
     "@rescript/react",
     "rescript-relay",
-    "rescript-relay-router",
-    "@rescript/core"
+    "rescript-relay-router"
   ],
   "bs-dev-dependencies": ["@rescript-relay-router/test-utils"],
-  "bsc-flags": ["-open RescriptCore"],
+  "bsc-flags": [],
   "pinned-dependencies": ["rescript-relay-router"]
 }