chore(deps): bump the npm_and_yarn group across 2 directories with 1 update

Bumps the npm_and_yarn group with 1 update in the /packages/sdk/vercel/examples/complete directory: [next](https://github.com/vercel/next.js).
Bumps the npm_and_yarn group with 1 update in the /packages/sdk/vercel/examples/route-handler directory: [next](https://github.com/vercel/next.js).


Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

Updates `next` from 15.5.18 to 15.5.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](vercel/next.js@v15.5.18...v15.5.21)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
- dependency-name: next
  dependency-version: 15.5.21
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/sdk/react/contract-tests/package.json

@@ -13,7 +13,7 @@
   "dependencies": {
     "@launchdarkly/js-contract-test-utils": "workspace:^",
     "@launchdarkly/react-sdk": "workspace:^",
-    "next": "16.2.11",
+    "next": "16.2.12",
     "react": "19.2.3",
     "react-dom": "19.2.3"
   },

packages/sdk/vercel/examples/complete/package.json

@@ -14,7 +14,7 @@
     "@vercel/edge-config": "^1.5.0",
     "launchdarkly-js-client-sdk": "^3.1.3",
     "launchdarkly-react-client-sdk": "^3.0.6",
-    "next": "15.5.18",
+    "next": "15.5.21",
     "react": "18.2.0",
     "react-dom": "18.2.0"
   },

packages/sdk/vercel/examples/route-handler/package.json

@@ -11,7 +11,7 @@
   "dependencies": {
     "@launchdarkly/vercel-server-sdk": "workspace:^",
     "@vercel/edge-config": "^1.5.0",
-    "next": "15.5.18",
+    "next": "15.5.21",
     "react": "^18.2.0",
     "react-dom": "18.2.0"
   },