AC-1685: Fix Integration Tests to be compatible with PHP 8.1

- update path to unit tests to work on composer installation

Author: xmav

dev/tests/unit/phpunit.xml.dist

@@ -31,7 +31,7 @@
             <exclude>../../../app/code/Magento/Indexer/Test/Unit</exclude>
         </testsuite>
         <testsuite name="Magento_Unit_Tests_App_Code_Indexer">
-            <directory>../../../app/code/Magento/Indexer/Test/Unit</directory>
+            <directory>../../../app/code/*/Indexer/Test/Unit</directory>
         </testsuite>
         <testsuite name="Magento_Unit_Tests_Other">
             <directory>../../../lib/internal/*/*/Test/Unit</directory>