meta: bump shiki from 1.10.3 to 1.15.2 (#7019)

Bumps [shiki](https://github.com/shikijs/shiki/tree/HEAD/packages/shiki) from 1.10.3 to 1.15.2.
- [Release notes](https://github.com/shikijs/shiki/releases)
- [Changelog](https://github.com/shikijs/shiki/blob/main/CHANGELOG.md)
- [Commits](https://github.com/shikijs/shiki/commits/v1.15.2/packages/shiki)

---
updated-dependencies:
- dependency-name: shiki
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

apps/site/package.json

@@ -81,7 +81,7 @@
     "remark-gfm": "~4.0.0",
     "remark-reading-time": "~2.0.1",
     "semver": "~7.6.0",
-    "shiki": "~1.10.1",
+    "shiki": "~1.15.2",
     "tailwindcss": "^3.4.7",
     "typescript": "~5.5.3",
     "unist-util-visit": "~5.0.0",