build(deps): Update saloonphp/saloon requirement from ^3.14 to ^4.0 (#20)

Updates the requirements on [saloonphp/saloon](https://github.com/saloonphp/saloon) to permit the latest version.
- [Release notes](https://github.com/saloonphp/saloon/releases)
- [Commits](saloonphp/saloon@v3.14.0...v4.0.0)

---
updated-dependencies:
- dependency-name: saloonphp/saloon
  dependency-version: 4.0.0
  dependency-type: direct:production
...

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Author: dependabot[bot]

composer.json

@@ -33,7 +33,7 @@
         "psr-discovery/event-dispatcher-implementations": "^1.1",
         "react/async": "^4.3",
         "saloonphp/cache-plugin": "^3.0",
-        "saloonphp/saloon": "^3.14",
+        "saloonphp/saloon": "^4.0",
         "spatie/laravel-package-tools": "^1.17",
         "spatie/yaml-front-matter": "^2.1"
     },