chore: update Strapi packages to 5.31.2 and revert workflow changes

- Update @strapi packages from 5.30.1 to 5.31.2 in playground
- Revert playground dependency back to yalc link (was temporarily file:..)
- Remove continue-on-error from E2E tests to properly fail on errors
- Keep .nvmrc for Node version consistency across environments

Author: MSACC

.github/workflows/tests.yml

@@ -49,7 +49,6 @@ jobs:
       - name: Run integration tests
         run: yarn run -s test:integration
       - name: Run end-to-end tests
-        continue-on-error: true
         uses: cypress-io/github-action@v6
         with:
           start: yarn playground:start

playground/package.json

@@ -21,14 +21,14 @@
     "yalc": "^1.0.0-pre.53"
   },
   "dependencies": {
-    "@strapi/plugin-cloud": "5.30.1",
-    "@strapi/plugin-users-permissions": "5.30.1",
-    "@strapi/strapi": "5.30.1",
+    "@strapi/plugin-cloud": "5.31.2",
+    "@strapi/plugin-users-permissions": "5.31.2",
+    "@strapi/strapi": "5.31.2",
     "better-sqlite3": "11.3.0",
     "react": "^18.0.0",
     "react-dom": "^18.0.0",
     "react-router-dom": "^6.0.0",
-    "strapi-plugin-config-sync": "file:..",
+    "strapi-plugin-config-sync": "link:.yalc/strapi-plugin-config-sync",
     "styled-components": "^6.0.0"
   },
   "author": {