Bump specberus from 11.1.6 to 11.2.1 (#1196)

Bumps [specberus](https://github.com/w3c/specberus) from 11.1.6 to 11.2.1.
- [Release notes](https://github.com/w3c/specberus/releases)
- [Commits](w3c/specberus@v11.1.6...v11.2.1)

---
updated-dependencies:
- dependency-name: specberus
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -34,7 +34,7 @@
     "passport-http": "0.3",
     "promise": "8.3.0",
     "request": "2.88.2",
-    "specberus": "11.1.6",
+    "specberus": "11.2.1",
     "tar-stream": "3.1.1",
     "uuid": "9.0.0"
   },