build(deps-dev): bump phpunit/phpunit from 9.6.8 to 10.2.1 (#470)

Author: dependabot[bot]

composer.json

@@ -31,7 +31,7 @@
   },
   "require-dev": {
     "lunr/halo": "dev-master",
-    "phpunit/phpunit": "~9.6",
+    "phpunit/phpunit": "~10.2",
     "theseer/autoload": "~1.0",
     "phing/phing": "~2.0",
     "phpstan/phpstan": "^1.2.0",