feat!: next.js 15, react 19, react compiler support (#6429)

**BREAKING:**
- bumps minimum required next.js version from `14.3.0-canary.68` to
`15.0.0-rc.0`
- bumps minimum required react and react-dom versions to `19.0.0
`(`19.0.0-rc-f994737d14-20240522` should be used)
- `@types/react` and `@types/react-dom` have to be bumped to
`npm:types-react@19.0.0-beta.2` using overrides and pnpm overrides, if
you want correct types. You can find an example of this here:
https://github.com/payloadcms/payload/pull/6429/files#diff-10cb9e57a77733f174ee2888587281e94c31f79e434aa3f932a8ec72fa7a5121L32

## Issues

- Bunch of todos for our react-select package which is having type
issues. Works fine, just type issues. Their type defs are importing JSX
in a weird way, we likely just have to wait until they fix them in a
future update.

packages/richtext-slate/.swcrc

@@ -7,6 +7,15 @@
       "syntax": "typescript",
       "tsx": true,
       "dts": true
+    },
+    "transform": {
+      "react": {
+        "runtime": "automatic",
+        "pragmaFrag": "React.Fragment",
+        "throwIfNamespace": true,
+        "development": false,
+        "useBuiltins": true
+      }
     }
   },
   "module": {

packages/richtext-slate/package.json

@@ -44,14 +44,15 @@
     "@payloadcms/ui": "workspace:*",
     "@types/is-hotkey": "^0.1.10",
     "@types/node": "20.12.5",
-    "@types/react": "18.3.2",
+    "@types/react": "npm:types-react@19.0.0-beta.2",
+    "@types/react-dom": "npm:types-react-dom@19.0.0-beta.2",
     "payload": "workspace:*"
   },
   "peerDependencies": {
     "@payloadcms/translations": "workspace:*",
     "@payloadcms/ui": "workspace:*",
     "payload": "workspace:*",
-    "react": "^18.0.0 || ^19.0.0"
+    "react": "^19.0.0 || ^19.0.0-rc-f994737d14-20240522"
   },
   "engines": {
     "node": ">=18.20.2"
@@ -67,5 +68,9 @@
     "main": "./dist/index.js",
     "registry": "https://registry.npmjs.org/",
     "types": "./dist/index.d.ts"
+  },
+  "overrides": {
+    "@types/react": "npm:types-react@19.0.0-beta.2",
+    "@types/react-dom": "npm:types-react-dom@19.0.0-beta.2"
   }
 }

packages/richtext-slate/tsconfig.json

@@ -6,7 +6,7 @@
     "emitDeclarationOnly": true,
     "outDir": "./dist" /* Specify an output folder for all emitted files. */,
     "rootDir": "./src" /* Specify the root folder within your source files. */,
-    "jsx": "react"
+    "jsx": "react-jsx"
   },
   "exclude": [
     "dist",