Merge pull request #494 from reactjs/dependabot/npm_and_yarn/next-15.5.21

Bump next from 15.1.12 to 15.5.21

Author: Zorig

package.json

@@ -36,7 +36,7 @@
     "classnames": "^2.2.6",
     "debounce": "^1.2.1",
     "github-slugger": "^1.3.0",
-    "next": "15.1.12",
+    "next": "15.5.21",
     "next-remote-watch": "^1.0.0",
     "parse-numeric-range": "^1.2.0",
     "raw-loader": "^4.0.2",