Fix test run fail due to AssertTest.php duplicate

The patch removes `<file>test/AssertTest.php</file>` duplicate
line from the `test/shared/phpunit.xml`.

Author: oleg-jukovec

test/shared/phpunit.xml

@@ -11,7 +11,6 @@
       <file>test/DMLTest.php</file>
       <file>test/MockTest.php</file>
       <file>test/MsgPackTest.php</file>
-      <file>test/AssertTest.php</file>
       <file>test/RandomTest.php</file>
     </testsuite>
   </testsuites>