Bump flat from 5.0.2 to 6.0.0

Bumps [flat](https://github.com/hughsk/flat) from 5.0.2 to 6.0.0.
- [Release notes](https://github.com/hughsk/flat/releases)
- [Commits](hughsk/flat@5.0.2...v6.0.0)

---
updated-dependencies:
- dependency-name: flat
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

package.json

@@ -32,7 +32,7 @@
     "@types/mustache": "^4.2.0",
     "@types/pretty": "^2.0.1",
     "fast-xml-parser": "^3.1.19",
-    "flat": "^5.0.2",
+    "flat": "^6.0.0",
     "he": "^1.2.0",
     "htmlparser2": "^9.0.0",
     "inspecjs": "^2.6.6",