build(deps-dev): bump file-type from 20.1.0 to 20.4.0

Bumps [file-type](https://github.com/sindresorhus/file-type) from 20.1.0 to 20.4.0.
- [Release notes](https://github.com/sindresorhus/file-type/releases)
- [Commits](sindresorhus/file-type@v20.1.0...v20.4.0)

---
updated-dependencies:
- dependency-name: file-type
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package-lock.json

@@ -31,7 +31,7 @@
     "@11ty/eleventy-plugin-rss": "^2.0.3",
     "@11ty/eleventy-plugin-syntaxhighlight": "^5.0.0",
     "@rollup/plugin-terser": "^0.4.4",
-    "file-type": "^20.1.0",
+    "file-type": "^20.4.0",
     "fs-extra": "^11.3.0",
     "jsdom": "^26.0.0",
     "luxon": "^3.5.0",