Bump the npm_and_yarn group across 2 directories with 1 update

Bumps the npm_and_yarn group with 1 update in the /apps/cache-testing directory: [next](https://github.com/vercel/next.js).
Bumps the npm_and_yarn group with 1 update in the /internal/next-common directory: [next](https://github.com/vercel/next.js).


Updates `next` from 14.2.15 to 14.2.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.15...v14.2.21)

Updates `next` from 14.2.15 to 14.2.21
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.15...v14.2.21)

---
updated-dependencies:
- dependency-name: next
  dependency-type: direct:production
  dependency-group: npm_and_yarn
- dependency-name: next
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

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

Author: dependabot[bot]

apps/cache-testing/package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "@neshca/cache-handler": "workspace:*",
     "axios": "1.7.9",
-    "next": "14.2.15",
+    "next": "14.2.21",
     "react": "18.3.1",
     "react-dom": "18.3.1",
     "redis": "4.7.0"

internal/next-common/package.json

@@ -8,7 +8,7 @@
     "types": "./src/next-common.ts"
   },
   "dependencies": {
-    "next": "14.2.15"
+    "next": "14.2.21"
   },
   "devDependencies": {
     "@repo/typescript-config": "workspace:*",