npm: bump remark-lint-no-duplicate-headings from 3.1.1 to 3.1.2

Bumps [remark-lint-no-duplicate-headings](https://github.com/remarkjs/remark-lint/tree/HEAD/packages/remark-lint-no-duplicate-headings) from 3.1.1 to 3.1.2.
- [Release notes](https://github.com/remarkjs/remark-lint/releases)
- [Changelog](https://github.com/remarkjs/remark-lint/blob/main/changelog.md)
- [Commits](https://github.com/remarkjs/remark-lint/commits/HEAD/packages/remark-lint-no-duplicate-headings)

---
updated-dependencies:
- dependency-name: remark-lint-no-duplicate-headings
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package.json

@@ -131,7 +131,7 @@
     "remark-lint-heading-whitespace": "1.0.0",
     "remark-lint-list-item-indent": "3.1.1",
     "remark-lint-no-dead-urls": "1.1.0",
-    "remark-lint-no-duplicate-headings": "3.1.1",
+    "remark-lint-no-duplicate-headings": "3.1.2",
     "remark-lint-write-good": "1.2.0",
     "remark-preset-lint-consistent": "5.1.1",
     "remark-preset-lint-markdown-style-guide": "5.1.2",