Update vimeo/psalm requirement from ^5.14.1 to ^5.15.0

Updates the requirements on [vimeo/psalm](https://github.com/vimeo/psalm) to permit the latest version.
- [Release notes](https://github.com/vimeo/psalm/releases)
- [Commits](vimeo/psalm@5.14.1...5.15.0)

---
updated-dependencies:
- dependency-name: vimeo/psalm
  dependency-type: direct:development
...

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

composer.json

@@ -41,7 +41,7 @@
         "pestphp/pest-plugin-parallel": "^1.2",
         "phpmd/phpmd": "^2.13",
         "squizlabs/php_codesniffer": "^3.7",
-        "vimeo/psalm": "^5.14.1"
+        "vimeo/psalm": "^5.15.0"
     },
     "autoload": {
         "files": [