Update phpunit config to phpunit10

Author: bastianschwarz

test/phpunit.dist.xml

@@ -15,8 +15,13 @@
   ~ limitations under the License.
   ~
   -->
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" colors="true" bootstrap="./../vendor/autoload.php"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
+<phpunit
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd"
+  colors="true"
+  bootstrap="./../vendor/autoload.php"
+  cacheDirectory="../.cache/phpunit"
+>
   <coverage>
     <include>
       <directory suffix=".php">./../src</directory>