build(deps-dev): bump @firebase/auth-compat from 0.4.9 to 0.5.6

Bumps [@firebase/auth-compat](https://github.com/firebase/firebase-js-sdk/tree/HEAD/packages/auth-compat) from 0.4.9 to 0.5.6.
- [Release notes](https://github.com/firebase/firebase-js-sdk/releases)
- [Changelog](https://github.com/firebase/firebase-js-sdk/blob/master/packages/auth-compat/CHANGELOG.md)
- [Commits](https://github.com/firebase/firebase-js-sdk/commits/@firebase/auth-compat@0.5.6/packages/auth-compat)

---
updated-dependencies:
- dependency-name: "@firebase/auth-compat"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

package.json

@@ -214,7 +214,7 @@
   "devDependencies": {
     "@firebase/api-documenter": "^0.4.0",
     "@firebase/app-compat": "^0.2.1",
-    "@firebase/auth-compat": "^0.4.1",
+    "@firebase/auth-compat": "^0.5.6",
     "@firebase/auth-types": "^0.12.0",
     "@microsoft/api-extractor": "^7.11.2",
     "@types/bcrypt": "^5.0.0",