composer: update kint-php/kint requirement from ^4.0 to ^6.0

Updates the requirements on [kint-php/kint](https://github.com/kint-php/kint) to permit the latest version.
- [Release notes](https://github.com/kint-php/kint/releases)
- [Commits](kint-php/kint@4.0...6.0.1)

---
updated-dependencies:
- dependency-name: kint-php/kint
  dependency-version: 6.0.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -23,7 +23,7 @@
         "vitexsoftware/ease-fluentpdo": "^1.4",
         "vitexsoftware/ease-html-widgets": "^1.0",
         "spojenet/csas-accountsapi": "^0.7",
-        "kint-php/kint": "^4.0"
+        "kint-php/kint": "^6.0"
     },
     "require-dev": {
         "robmorgan/phinx": "^0.16",