templates: bump payload versions, upgrade next.js to 15.2.0, fix eslint errors (#11486)

- Ensures website templates build without eslint errors
- Upgrades all templates from Next.js 15.1.5 to 15.2.0
- Bumps all payload versions, updates all lockfiles to reference latest payload versions. The blank template was still installing 3.17.1 and the website template was installing 3.18.0
- Simplifies defaultLexical.ts

Author: AlessioGr

templates/_template/package.json

@@ -21,7 +21,7 @@
     "@payloadcms/richtext-lexical": "latest",
     "cross-env": "^7.0.3",
     "graphql": "^16.8.1",
-    "next": "15.1.5",
+    "next": "15.2.0",
     "payload": "latest",
     "react": "19.0.0",
     "react-dom": "19.0.0",
@@ -30,10 +30,10 @@
   "devDependencies": {
     "@eslint/eslintrc": "^3.2.0",
     "@types/node": "^22.5.4",
-    "@types/react": "19.0.7",
-    "@types/react-dom": "19.0.3",
+    "@types/react": "19.0.10",
+    "@types/react-dom": "19.0.4",
     "eslint": "^9.16.0",
-    "eslint-config-next": "15.1.5",
+    "eslint-config-next": "15.2.0",
     "prettier": "^3.4.2",
     "typescript": "5.7.3"
   },

templates/blank/package.json

@@ -21,7 +21,7 @@
     "@payloadcms/richtext-lexical": "latest",
     "cross-env": "^7.0.3",
     "graphql": "^16.8.1",
-    "next": "15.1.5",
+    "next": "15.2.0",
     "payload": "latest",
     "react": "19.0.0",
     "react-dom": "19.0.0",
@@ -30,10 +30,10 @@
   "devDependencies": {
     "@eslint/eslintrc": "^3.2.0",
     "@types/node": "^22.5.4",
-    "@types/react": "19.0.7",
-    "@types/react-dom": "19.0.3",
+    "@types/react": "19.0.10",
+    "@types/react-dom": "19.0.4",
     "eslint": "^9.16.0",
-    "eslint-config-next": "15.1.5",
+    "eslint-config-next": "15.2.0",
     "prettier": "^3.4.2",
     "typescript": "5.7.3"
   },