Fix PHPUnit config to restore Codecov support

Author: mbabker

.gitignore

@@ -2,6 +2,7 @@
 bin
 vendor
 composer.lock
+coverage.xml
 phpstan.neon
 .phpunit.result.cache
-tests/phpunit.xml
+phpunit.xml

phpunit.xml.dist

@@ -9,11 +9,11 @@
     processIsolation="false"
     stopOnFailure="false"
     bootstrap="./tests/bootstrap.php"
-    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd"
+    xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
 >
     <coverage>
         <include>
-            <directory>../src</directory>
+            <directory>./src</directory>
         </include>
     </coverage>
     <testsuites>