Update tomasvotruba/unused-public requirement || ^0.4.0

Updates the requirements on [tomasvotruba/unused-public](https://github.com/TomasVotruba/unused-public) to permit the latest version.
- [Commits](TomasVotruba/unused-public@0.3.9...0.4.0)

---
updated-dependencies:
- dependency-name: tomasvotruba/unused-public
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -25,7 +25,7 @@
         "rector/rector": "^1.0",
         "tightenco/duster": "^2.7 || ^3.0",
         "tomasvotruba/cognitive-complexity": "^0.2.3",
-        "tomasvotruba/unused-public": "^0.3.9"
+        "tomasvotruba/unused-public": "^0.3.9 || ^0.4.0"
     },
     "autoload": {
         "psr-4": {