Bump reffy from 18.7.1 to 18.7.3 (#1564)

Bumps [reffy](https://github.com/w3c/reffy) from 18.7.1 to 18.7.3.
- [Changelog](https://github.com/w3c/reffy/blob/main/CHANGELOG.md)
- [Commits](https://github.com/w3c/reffy/commits)

---
updated-dependencies:
- dependency-name: reffy
  dependency-version: 18.7.3
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package-lock.json

@@ -34,7 +34,7 @@
     "@webref/events": "file:packages/events",
     "@webref/idl": "file:packages/idl",
     "css-tree": "3.1.0",
-    "reffy": "18.7.1",
+    "reffy": "18.7.3",
     "rimraf": "6.0.1",
     "strudy": "^3.2.0",
     "webidl2": "24.4.1"