Update mockery/mockery requirement from ^1.4 to ^1.6

Updates the requirements on [mockery/mockery](https://github.com/mockery/mockery) to permit the latest version.
- [Release notes](https://github.com/mockery/mockery/releases)
- [Changelog](https://github.com/mockery/mockery/blob/1.6.x/CHANGELOG.md)
- [Commits](mockery/mockery@1.4.0...1.6.6)

---
updated-dependencies:
- dependency-name: mockery/mockery
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -45,7 +45,7 @@
         "test": "vendor/bin/phpunit"
     },
     "require-dev": {
-        "mockery/mockery": "^1.4",
+        "mockery/mockery": "^1.6",
         "orchestra/testbench": "^7.14",
         "vimeo/psalm": "4.24.0"
     },