Bump brace-expansion from 1.1.18 to 1.1.21 in /docs (#24596)

Bumps [brace-expansion](https://github.com/juliangruber/brace-expansion) from 1.1.18 to 1.1.21.
- [Release notes](https://github.com/juliangruber/brace-expansion/releases)
- [Commits](https://github.com/juliangruber/brace-expansion/compare/v1.1.18...v1.1.21)

---
updated-dependencies:
- dependency-name: brace-expansion
  dependency-version: 1.1.21
  dependency-type: indirect
...

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

docs/package-lock.json

@@ -7030,9 +7030,9 @@
       }
     },
     "node_modules/brace-expansion": {
-      "version": "1.1.18",
+      "version": "1.1.21",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.18.tgz",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.21.tgz",
-      "integrity": "sha512-Edep/X9fGqVNmzKBVsDYIOtD+z1tuezV70LBjdCst9Tqu76lsnvRiZ6oTic1n+/BIwX6QDGAO94PN4N2SADvtw==",
+      "integrity": "sha512-9zeA+KLZNNzglF2TPKRQEDyx6Yby7daAkuy8MiPzpXPsYDWi/DRM8jmwUDxokQjYqBpv5DgPiwD4h4ZZSy1Ujw==",
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^1.0.0",