Bump @next/mdx from 13.1.1 to 15.1.4

Bumps [@next/mdx](https://github.com/vercel/next.js/tree/HEAD/packages/next-mdx) from 13.1.1 to 15.1.4.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/commits/v15.1.4/packages/next-mdx)

---
updated-dependencies:
- dependency-name: "@next/mdx"
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -16,7 +16,7 @@
     "@hackclub/theme": "^0.3.3",
     "@mdx-js/loader": "^3.1.0",
     "@mdx-js/react": "^2.3.0",
-    "@next/mdx": "^13.1.1",
+    "@next/mdx": "^15.1.4",
     "airtable-plus": "^1.0.4",
     "leaflet": "^1.9.4",
     "next": "^15.1.3",

yarn.lock

@@ -361,10 +361,10 @@
   resolved "https://registry.yarnpkg.com/@next/env/-/env-15.1.3.tgz#bc747e041cd105170d4cae07cc802e20b4a0c153"
   integrity sha512-Q1tXwQCGWyA3ehMph3VO+E6xFPHDKdHFYosadt0F78EObYxPio0S09H9UGYznDe6Wc8eLKLG89GqcFJJDiK5xw==
 
-"@next/mdx@^13.1.1":
-  version "13.1.1"
-  resolved "https://registry.yarnpkg.com/@next/mdx/-/mdx-13.1.1.tgz#ca3daf4903a97af65b994d87da342395e488f349"
-  integrity sha512-a588olt++s7vcuhlgrNOBpZUqlbr9vr94NjA3ixM9AgL8fnwJ/GgxEMsrcsp2gPw91lzBlumBfjK6Lc3k3m23Q==
+"@next/mdx@^15.1.4":
+  version "15.1.4"
+  resolved "https://registry.yarnpkg.com/@next/mdx/-/mdx-15.1.4.tgz#d2b4b0c57794959a44d18d7d383a6931ed905912"
+  integrity sha512-GsmKCWPDW6Qas4/yL+zj7RLGrDsVu89F42/S9pVcPTvYmXNK1PqRT6H7outQy6Ox/AGB8As1lxPvk4dJmDIm7w==
   dependencies:
     source-map "^0.7.0"