Bump stylelint from 16.25.0 to 16.26.0

Bumps [stylelint](https://github.com/stylelint/stylelint) from 16.25.0 to 16.26.0.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint@16.25.0...16.26.0)

---
updated-dependencies:
- dependency-name: stylelint
  dependency-version: 16.26.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package-lock.json

@@ -32,7 +32,7 @@
   "devDependencies": {
     "@x-govuk/eslint-config": "^0.0.1",
     "prettier": "^3.6.2",
-    "stylelint": "^16.25.0",
+    "stylelint": "^16.26.0",
     "stylelint-config-gds": "^2.0.0"
   },
   "private": true,