Drop older versions of PHPUnit (9.x)

Signed-off-by: William Desportes <williamdes@wdes.fr>

Author: williamdes

.gitignore

@@ -4,3 +4,4 @@ build/
 composer.lock
 phpcs.xml
 .phpcs-cache
+.phpunit.result.cache

composer.json

@@ -30,7 +30,7 @@
         "phpstan/phpstan": "^1.10",
         "phpstan/phpstan-phpunit": "^1.3",
         "phpstan/phpstan-strict-rules": "^1.5",
-        "phpunit/phpunit": "^9.6"
+        "phpunit/phpunit": "^10"
     },
     "scripts": {
         "phpstan": "./vendor/bin/phpstan analyse",